9 files changed, 2593 insertions, 0 deletions
diff --git a/projects/10/ExpressionLessSquare/Main.jack b/projects/10/ExpressionLessSquare/Main.jack
new file mode 100644
index 0000000..94764ad
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/Main.jack
@@ -0,0 +1,28 @@
+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/10/ExpressionLessSquare/Main.jack
+
+/** Expressionless version of projects/10/Square/Main.jack. */
+
+class Main {
+    static boolean test;    // Added for testing -- there is no static keyword
+                            // in the Square files.
+
+    function void main() {
+        var SquareGame game;
+        let game = game;
+        do game.run();
+        do game.dispose();
+        return;
+    }
+
+    function void more() {  // Added to test Jack syntax that is not used in
+        var boolean b;      // the Square files.
+        if (b) {
+        }
+        else {              // There is no else keyword in the Square files.
+        }
+        return;
+    }
+}
diff --git a/projects/10/ExpressionLessSquare/Main.xml b/projects/10/ExpressionLessSquare/Main.xml
new file mode 100644
index 0000000..f71a0ef
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/Main.xml
@@ -0,0 +1,114 @@
+<class>
+  <keyword> class </keyword>
+  <identifier> Main </identifier>
+  <symbol> { </symbol>
+  <classVarDec>
+    <keyword> static </keyword>
+    <keyword> boolean </keyword>
+    <identifier> test </identifier>
+    <symbol> ; </symbol>
+  </classVarDec>
+  <subroutineDec>
+    <keyword> function </keyword>
+    <keyword> void </keyword>
+    <identifier> main </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <varDec>
+        <keyword> var </keyword>
+        <identifier> SquareGame </identifier>
+        <identifier> game </identifier>
+        <symbol> ; </symbol>
+      </varDec>
+      <statements>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> game </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> game </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> game </identifier>
+          <symbol> . </symbol>
+          <identifier> run </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> game </identifier>
+          <symbol> . </symbol>
+          <identifier> dispose </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> function </keyword>
+    <keyword> void </keyword>
+    <identifier> more </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <varDec>
+        <keyword> var </keyword>
+        <keyword> boolean </keyword>
+        <identifier> b </identifier>
+        <symbol> ; </symbol>
+      </varDec>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> b </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+          </statements>
+          <symbol> } </symbol>
+          <keyword> else </keyword>
+          <symbol> { </symbol>
+          <statements>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <symbol> } </symbol>
+</class>
diff --git a/projects/10/ExpressionLessSquare/MainT.xml b/projects/10/ExpressionLessSquare/MainT.xml
new file mode 100644
index 0000000..441dfed
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/MainT.xml
@@ -0,0 +1,64 @@
+<tokens>
+<keyword> class </keyword>
+<identifier> Main </identifier>
+<symbol> { </symbol>
+<keyword> static </keyword>
+<keyword> boolean </keyword>
+<identifier> test </identifier>
+<symbol> ; </symbol>
+<keyword> function </keyword>
+<keyword> void </keyword>
+<identifier> main </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> var </keyword>
+<identifier> SquareGame </identifier>
+<identifier> game </identifier>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> game </identifier>
+<symbol> = </symbol>
+<identifier> game </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> game </identifier>
+<symbol> . </symbol>
+<identifier> run </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> game </identifier>
+<symbol> . </symbol>
+<identifier> dispose </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> function </keyword>
+<keyword> void </keyword>
+<identifier> more </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> var </keyword>
+<keyword> boolean </keyword>
+<identifier> b </identifier>
+<symbol> ; </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> b </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<symbol> } </symbol>
+<keyword> else </keyword>
+<symbol> { </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<symbol> } </symbol>
+</tokens>
diff --git a/projects/10/ExpressionLessSquare/Square.jack b/projects/10/ExpressionLessSquare/Square.jack
new file mode 100644
index 0000000..33a54ad
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/Square.jack
@@ -0,0 +1,99 @@
+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+/// File name: projects/10/ExpressionLessSquare/Square.jack
+
+/** Expressionless version of projects/10/Square/Square.jack. */
+
+class Square {
+
+   field int x, y; 
+   field int size; 
+
+   constructor Square new(int Ax, int Ay, int Asize) {
+      let x = Ax;
+      let y = Ay;
+      let size = Asize;
+      do draw();
+      return x;
+   }
+
+   method void dispose() {
+      do Memory.deAlloc(this);
+      return;
+   }
+
+   method void draw() {
+      do Screen.setColor(x);
+      do Screen.drawRectangle(x, y, x, y);
+      return;
+   }
+
+   method void erase() {
+      do Screen.setColor(x);
+      do Screen.drawRectangle(x, y, x, y);
+      return;
+   }
+
+   method void incSize() {
+      if (x) {
+         do erase();
+         let size = size;
+         do draw();
+      }
+      return;
+   }
+
+   method void decSize() {
+      if (size) {
+         do erase();
+         let size = size;
+         do draw();
+      }
+      return;
+   }
+
+   method void moveUp() {
+      if (y) {
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+         let y = y;
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+      }
+      return;
+   }
+
+   method void moveDown() {
+      if (y) {
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+         let y = y;
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+      }
+      return;
+   }
+
+   method void moveLeft() {
+      if (x) {
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+         let x = x;
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+      }
+      return;
+   }
+
+   method void moveRight() {
+      if (x) {
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+         let x = x;
+         do Screen.setColor(x);
+         do Screen.drawRectangle(x, y, x, y);
+      }
+      return;
+   }
+}  
diff --git a/projects/10/ExpressionLessSquare/Square.xml b/projects/10/ExpressionLessSquare/Square.xml
new file mode 100644
index 0000000..ed0e6ec
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/Square.xml
@@ -0,0 +1,967 @@
+<class>
+  <keyword> class </keyword>
+  <identifier> Square </identifier>
+  <symbol> { </symbol>
+  <classVarDec>
+    <keyword> field </keyword>
+    <keyword> int </keyword>
+    <identifier> x </identifier>
+    <symbol> , </symbol>
+    <identifier> y </identifier>
+    <symbol> ; </symbol>
+  </classVarDec>
+  <classVarDec>
+    <keyword> field </keyword>
+    <keyword> int </keyword>
+    <identifier> size </identifier>
+    <symbol> ; </symbol>
+  </classVarDec>
+  <subroutineDec>
+    <keyword> constructor </keyword>
+    <identifier> Square </identifier>
+    <identifier> new </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+      <keyword> int </keyword>
+      <identifier> Ax </identifier>
+      <symbol> , </symbol>
+      <keyword> int </keyword>
+      <identifier> Ay </identifier>
+      <symbol> , </symbol>
+      <keyword> int </keyword>
+      <identifier> Asize </identifier>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> x </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> Ax </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> y </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> Ay </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> size </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> Asize </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> draw </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <expression>
+            <term>
+              <identifier> x </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> dispose </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Memory </identifier>
+          <symbol> . </symbol>
+          <identifier> deAlloc </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <keyword> this </keyword>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> draw </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Screen </identifier>
+          <symbol> . </symbol>
+          <identifier> setColor </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <identifier> x </identifier>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Screen </identifier>
+          <symbol> . </symbol>
+          <identifier> drawRectangle </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <identifier> x </identifier>
+              </term>
+            </expression>
+            <symbol> , </symbol>
+            <expression>
+              <term>
+                <identifier> y </identifier>
+              </term>
+            </expression>
+            <symbol> , </symbol>
+            <expression>
+              <term>
+                <identifier> x </identifier>
+              </term>
+            </expression>
+            <symbol> , </symbol>
+            <expression>
+              <term>
+                <identifier> y </identifier>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> erase </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Screen </identifier>
+          <symbol> . </symbol>
+          <identifier> setColor </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <identifier> x </identifier>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Screen </identifier>
+          <symbol> . </symbol>
+          <identifier> drawRectangle </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <identifier> x </identifier>
+              </term>
+            </expression>
+            <symbol> , </symbol>
+            <expression>
+              <term>
+                <identifier> y </identifier>
+              </term>
+            </expression>
+            <symbol> , </symbol>
+            <expression>
+              <term>
+                <identifier> x </identifier>
+              </term>
+            </expression>
+            <symbol> , </symbol>
+            <expression>
+              <term>
+                <identifier> y </identifier>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> incSize </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> x </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> erase </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <letStatement>
+              <keyword> let </keyword>
+              <identifier> size </identifier>
+              <symbol> = </symbol>
+              <expression>
+                <term>
+                  <identifier> size </identifier>
+                </term>
+              </expression>
+              <symbol> ; </symbol>
+            </letStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> draw </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> decSize </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> size </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> erase </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <letStatement>
+              <keyword> let </keyword>
+              <identifier> size </identifier>
+              <symbol> = </symbol>
+              <expression>
+                <term>
+                  <identifier> size </identifier>
+                </term>
+              </expression>
+              <symbol> ; </symbol>
+            </letStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> draw </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> moveUp </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> y </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <letStatement>
+              <keyword> let </keyword>
+              <identifier> y </identifier>
+              <symbol> = </symbol>
+              <expression>
+                <term>
+                  <identifier> y </identifier>
+                </term>
+              </expression>
+              <symbol> ; </symbol>
+            </letStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> moveDown </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> y </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <letStatement>
+              <keyword> let </keyword>
+              <identifier> y </identifier>
+              <symbol> = </symbol>
+              <expression>
+                <term>
+                  <identifier> y </identifier>
+                </term>
+              </expression>
+              <symbol> ; </symbol>
+            </letStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> moveLeft </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> x </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <letStatement>
+              <keyword> let </keyword>
+              <identifier> x </identifier>
+              <symbol> = </symbol>
+              <expression>
+                <term>
+                  <identifier> x </identifier>
+                </term>
+              </expression>
+              <symbol> ; </symbol>
+            </letStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> moveRight </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> x </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <letStatement>
+              <keyword> let </keyword>
+              <identifier> x </identifier>
+              <symbol> = </symbol>
+              <expression>
+                <term>
+                  <identifier> x </identifier>
+                </term>
+              </expression>
+              <symbol> ; </symbol>
+            </letStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> setColor </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> Screen </identifier>
+              <symbol> . </symbol>
+              <identifier> drawRectangle </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> x </identifier>
+                  </term>
+                </expression>
+                <symbol> , </symbol>
+                <expression>
+                  <term>
+                    <identifier> y </identifier>
+                  </term>
+                </expression>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <symbol> } </symbol>
+</class>
diff --git a/projects/10/ExpressionLessSquare/SquareGame.jack b/projects/10/ExpressionLessSquare/SquareGame.jack
new file mode 100644
index 0000000..2866f0d
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/SquareGame.jack
@@ -0,0 +1,60 @@
+// This file is part of www.nand2tetris.org
+// and the book "The Elements of Computing Systems"
+// by Nisan and Schocken, MIT Press.
+// File name: projects/10/ExpressionLessSquare/SquareGame.jack
+
+/** Expressionless version of projects/10/Square/SquareGame.jack. */
+
+class SquareGame {
+   field Square square; 
+   field int direction; 
+
+   constructor SquareGame new() {
+      let square = square;
+      let direction = direction;
+      return square;
+   }
+
+   method void dispose() {
+      do square.dispose();
+      do Memory.deAlloc(square);
+      return;
+   }
+
+   method void moveSquare() {
+      if (direction) { do square.moveUp(); }
+      if (direction) { do square.moveDown(); }
+      if (direction) { do square.moveLeft(); }
+      if (direction) { do square.moveRight(); }
+      do Sys.wait(direction);
+      return;
+   }
+
+   method void run() {
+      var char key;
+      var boolean exit;
+      
+      let exit = key;
+      while (exit) {
+         while (key) {
+            let key = key;
+            do moveSquare();
+         }
+
+         if (key) { let exit = exit; }
+         if (key) { do square.decSize(); }
+         if (key) { do square.incSize(); }
+         if (key) { let direction = exit; }
+         if (key) { let direction = key; }
+         if (key) { let direction = square; }
+         if (key) { let direction = direction; }
+
+         while (key) {
+            let key = key;
+            do moveSquare();
+         }
+      }
+      return;
+    }
+}
+
diff --git a/projects/10/ExpressionLessSquare/SquareGame.xml b/projects/10/ExpressionLessSquare/SquareGame.xml
new file mode 100644
index 0000000..288c6cd
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/SquareGame.xml
@@ -0,0 +1,544 @@
+<class>
+  <keyword> class </keyword>
+  <identifier> SquareGame </identifier>
+  <symbol> { </symbol>
+  <classVarDec>
+    <keyword> field </keyword>
+    <identifier> Square </identifier>
+    <identifier> square </identifier>
+    <symbol> ; </symbol>
+  </classVarDec>
+  <classVarDec>
+    <keyword> field </keyword>
+    <keyword> int </keyword>
+    <identifier> direction </identifier>
+    <symbol> ; </symbol>
+  </classVarDec>
+  <subroutineDec>
+    <keyword> constructor </keyword>
+    <identifier> SquareGame </identifier>
+    <identifier> new </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> square </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> square </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> direction </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> direction </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <expression>
+            <term>
+              <identifier> square </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> dispose </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> square </identifier>
+          <symbol> . </symbol>
+          <identifier> dispose </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Memory </identifier>
+          <symbol> . </symbol>
+          <identifier> deAlloc </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <identifier> square </identifier>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> moveSquare </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <statements>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> direction </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> square </identifier>
+              <symbol> . </symbol>
+              <identifier> moveUp </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> direction </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> square </identifier>
+              <symbol> . </symbol>
+              <identifier> moveDown </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> direction </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> square </identifier>
+              <symbol> . </symbol>
+              <identifier> moveLeft </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <ifStatement>
+          <keyword> if </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> direction </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <doStatement>
+              <keyword> do </keyword>
+              <identifier> square </identifier>
+              <symbol> . </symbol>
+              <identifier> moveRight </identifier>
+              <symbol> ( </symbol>
+              <expressionList>
+              </expressionList>
+              <symbol> ) </symbol>
+              <symbol> ; </symbol>
+            </doStatement>
+          </statements>
+          <symbol> } </symbol>
+        </ifStatement>
+        <doStatement>
+          <keyword> do </keyword>
+          <identifier> Sys </identifier>
+          <symbol> . </symbol>
+          <identifier> wait </identifier>
+          <symbol> ( </symbol>
+          <expressionList>
+            <expression>
+              <term>
+                <identifier> direction </identifier>
+              </term>
+            </expression>
+          </expressionList>
+          <symbol> ) </symbol>
+          <symbol> ; </symbol>
+        </doStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <subroutineDec>
+    <keyword> method </keyword>
+    <keyword> void </keyword>
+    <identifier> run </identifier>
+    <symbol> ( </symbol>
+    <parameterList>
+    </parameterList>
+    <symbol> ) </symbol>
+    <subroutineBody>
+      <symbol> { </symbol>
+      <varDec>
+        <keyword> var </keyword>
+        <keyword> char </keyword>
+        <identifier> key </identifier>
+        <symbol> ; </symbol>
+      </varDec>
+      <varDec>
+        <keyword> var </keyword>
+        <keyword> boolean </keyword>
+        <identifier> exit </identifier>
+        <symbol> ; </symbol>
+      </varDec>
+      <statements>
+        <letStatement>
+          <keyword> let </keyword>
+          <identifier> exit </identifier>
+          <symbol> = </symbol>
+          <expression>
+            <term>
+              <identifier> key </identifier>
+            </term>
+          </expression>
+          <symbol> ; </symbol>
+        </letStatement>
+        <whileStatement>
+          <keyword> while </keyword>
+          <symbol> ( </symbol>
+          <expression>
+            <term>
+              <identifier> exit </identifier>
+            </term>
+          </expression>
+          <symbol> ) </symbol>
+          <symbol> { </symbol>
+          <statements>
+            <whileStatement>
+              <keyword> while </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> key </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> key </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+                <doStatement>
+                  <keyword> do </keyword>
+                  <identifier> moveSquare </identifier>
+                  <symbol> ( </symbol>
+                  <expressionList>
+                  </expressionList>
+                  <symbol> ) </symbol>
+                  <symbol> ; </symbol>
+                </doStatement>
+              </statements>
+              <symbol> } </symbol>
+            </whileStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> exit </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> exit </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <doStatement>
+                  <keyword> do </keyword>
+                  <identifier> square </identifier>
+                  <symbol> . </symbol>
+                  <identifier> decSize </identifier>
+                  <symbol> ( </symbol>
+                  <expressionList>
+                  </expressionList>
+                  <symbol> ) </symbol>
+                  <symbol> ; </symbol>
+                </doStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <doStatement>
+                  <keyword> do </keyword>
+                  <identifier> square </identifier>
+                  <symbol> . </symbol>
+                  <identifier> incSize </identifier>
+                  <symbol> ( </symbol>
+                  <expressionList>
+                  </expressionList>
+                  <symbol> ) </symbol>
+                  <symbol> ; </symbol>
+                </doStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> direction </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> exit </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> direction </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> key </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> direction </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> square </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <ifStatement>
+              <keyword> if </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> direction </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> direction </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+              </statements>
+              <symbol> } </symbol>
+            </ifStatement>
+            <whileStatement>
+              <keyword> while </keyword>
+              <symbol> ( </symbol>
+              <expression>
+                <term>
+                  <identifier> key </identifier>
+                </term>
+              </expression>
+              <symbol> ) </symbol>
+              <symbol> { </symbol>
+              <statements>
+                <letStatement>
+                  <keyword> let </keyword>
+                  <identifier> key </identifier>
+                  <symbol> = </symbol>
+                  <expression>
+                    <term>
+                      <identifier> key </identifier>
+                    </term>
+                  </expression>
+                  <symbol> ; </symbol>
+                </letStatement>
+                <doStatement>
+                  <keyword> do </keyword>
+                  <identifier> moveSquare </identifier>
+                  <symbol> ( </symbol>
+                  <expressionList>
+                  </expressionList>
+                  <symbol> ) </symbol>
+                  <symbol> ; </symbol>
+                </doStatement>
+              </statements>
+              <symbol> } </symbol>
+            </whileStatement>
+          </statements>
+          <symbol> } </symbol>
+        </whileStatement>
+        <returnStatement>
+          <keyword> return </keyword>
+          <symbol> ; </symbol>
+        </returnStatement>
+      </statements>
+      <symbol> } </symbol>
+    </subroutineBody>
+  </subroutineDec>
+  <symbol> } </symbol>
+</class>
diff --git a/projects/10/ExpressionLessSquare/SquareGameT.xml b/projects/10/ExpressionLessSquare/SquareGameT.xml
new file mode 100644
index 0000000..278a8a9
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/SquareGameT.xml
@@ -0,0 +1,268 @@
+<tokens>
+<keyword> class </keyword>
+<identifier> SquareGame </identifier>
+<symbol> { </symbol>
+<keyword> field </keyword>
+<identifier> Square </identifier>
+<identifier> square </identifier>
+<symbol> ; </symbol>
+<keyword> field </keyword>
+<keyword> int </keyword>
+<identifier> direction </identifier>
+<symbol> ; </symbol>
+<keyword> constructor </keyword>
+<identifier> SquareGame </identifier>
+<identifier> new </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> square </identifier>
+<symbol> = </symbol>
+<identifier> square </identifier>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> direction </identifier>
+<symbol> = </symbol>
+<identifier> direction </identifier>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<identifier> square </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> dispose </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> dispose </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Memory </identifier>
+<symbol> . </symbol>
+<identifier> deAlloc </identifier>
+<symbol> ( </symbol>
+<identifier> square </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> moveSquare </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> direction </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> moveUp </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> direction </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> moveDown </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> direction </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> moveLeft </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> direction </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> moveRight </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> do </keyword>
+<identifier> Sys </identifier>
+<symbol> . </symbol>
+<identifier> wait </identifier>
+<symbol> ( </symbol>
+<identifier> direction </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> run </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> var </keyword>
+<keyword> char </keyword>
+<identifier> key </identifier>
+<symbol> ; </symbol>
+<keyword> var </keyword>
+<keyword> boolean </keyword>
+<identifier> exit </identifier>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> exit </identifier>
+<symbol> = </symbol>
+<identifier> key </identifier>
+<symbol> ; </symbol>
+<keyword> while </keyword>
+<symbol> ( </symbol>
+<identifier> exit </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> while </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> key </identifier>
+<symbol> = </symbol>
+<identifier> key </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> moveSquare </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> exit </identifier>
+<symbol> = </symbol>
+<identifier> exit </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> decSize </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> square </identifier>
+<symbol> . </symbol>
+<identifier> incSize </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> direction </identifier>
+<symbol> = </symbol>
+<identifier> exit </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> direction </identifier>
+<symbol> = </symbol>
+<identifier> key </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> direction </identifier>
+<symbol> = </symbol>
+<identifier> square </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> direction </identifier>
+<symbol> = </symbol>
+<identifier> direction </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> while </keyword>
+<symbol> ( </symbol>
+<identifier> key </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> key </identifier>
+<symbol> = </symbol>
+<identifier> key </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> moveSquare </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<symbol> } </symbol>
+</tokens>
diff --git a/projects/10/ExpressionLessSquare/SquareT.xml b/projects/10/ExpressionLessSquare/SquareT.xml
new file mode 100644
index 0000000..cd03a1e
--- /dev/null
+++ b/projects/10/ExpressionLessSquare/SquareT.xml
@@ -0,0 +1,449 @@
+<tokens>
+<keyword> class </keyword>
+<identifier> Square </identifier>
+<symbol> { </symbol>
+<keyword> field </keyword>
+<keyword> int </keyword>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ; </symbol>
+<keyword> field </keyword>
+<keyword> int </keyword>
+<identifier> size </identifier>
+<symbol> ; </symbol>
+<keyword> constructor </keyword>
+<identifier> Square </identifier>
+<identifier> new </identifier>
+<symbol> ( </symbol>
+<keyword> int </keyword>
+<identifier> Ax </identifier>
+<symbol> , </symbol>
+<keyword> int </keyword>
+<identifier> Ay </identifier>
+<symbol> , </symbol>
+<keyword> int </keyword>
+<identifier> Asize </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> let </keyword>
+<identifier> x </identifier>
+<symbol> = </symbol>
+<identifier> Ax </identifier>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> y </identifier>
+<symbol> = </symbol>
+<identifier> Ay </identifier>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> size </identifier>
+<symbol> = </symbol>
+<identifier> Asize </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> draw </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<identifier> x </identifier>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> dispose </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Memory </identifier>
+<symbol> . </symbol>
+<identifier> deAlloc </identifier>
+<symbol> ( </symbol>
+<keyword> this </keyword>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> draw </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> erase </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> incSize </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> erase </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> size </identifier>
+<symbol> = </symbol>
+<identifier> size </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> draw </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> decSize </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> size </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> erase </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> size </identifier>
+<symbol> = </symbol>
+<identifier> size </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> draw </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> moveUp </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> y </identifier>
+<symbol> = </symbol>
+<identifier> y </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> moveDown </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> y </identifier>
+<symbol> = </symbol>
+<identifier> y </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> moveLeft </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> x </identifier>
+<symbol> = </symbol>
+<identifier> x </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> method </keyword>
+<keyword> void </keyword>
+<identifier> moveRight </identifier>
+<symbol> ( </symbol>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> if </keyword>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> { </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> let </keyword>
+<identifier> x </identifier>
+<symbol> = </symbol>
+<identifier> x </identifier>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> setColor </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<keyword> do </keyword>
+<identifier> Screen </identifier>
+<symbol> . </symbol>
+<identifier> drawRectangle </identifier>
+<symbol> ( </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> , </symbol>
+<identifier> x </identifier>
+<symbol> , </symbol>
+<identifier> y </identifier>
+<symbol> ) </symbol>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<keyword> return </keyword>
+<symbol> ; </symbol>
+<symbol> } </symbol>
+<symbol> } </symbol>
+</tokens>