diff --git a/src/shared/function.js b/src/shared/function.js
index 1ece43f91..630b20356 100644
--- a/src/shared/function.js
+++ b/src/shared/function.js
@@ -659,14 +659,14 @@ var PostScriptEvaluator = (function PostScriptEvaluatorClosure() {
             break;
           case 'neg':
             a = stack.pop();
-            stack.push(-b);
+            stack.push(-a);
             break;
           case 'not':
             a = stack.pop();
-            if (isBool(a) && isBool(b)) {
-              stack.push(a && b);
+            if (isBool(a)) {
+              stack.push(!a);
             } else {
-              stack.push(a & b);
+              stack.push(~a);
             }
             break;
           case 'or':
diff --git a/test/unit/function_spec.js b/test/unit/function_spec.js
index 10d0a38c1..fb6912311 100644
--- a/test/unit/function_spec.js
+++ b/test/unit/function_spec.js
@@ -81,7 +81,7 @@ describe('function', function() {
     });
     it('handles missing brackets', function() {
       expect(function() { parse('{'); }).toThrow(
-                  new Error('Unexpected symbol: found undefined expected 1.'));
+        new Error('Unexpected symbol: found undefined expected 1.'));
     });
     it('handles junk after the end', function() {
       var number = 3.3;
@@ -142,21 +142,41 @@ describe('function', function() {
       var expectedStack = [3];
       expect(stack).toMatchArray(expectedStack);
     });
-    it('boolean ands', function() {
+    it('boolean and', function() {
       var stack = evaluate('{ true false and }');
       var expectedStack = [false];
       expect(stack).toMatchArray(expectedStack);
     });
-    it('bitwise ands', function() {
+    it('bitwise and', function() {
       var stack = evaluate('{ 254 1 and }');
       var expectedStack = [254 & 1];
       expect(stack).toMatchArray(expectedStack);
     });
-    // TODO atan
-    // TODO bitshift
-    // TODO ceiling
-    // TODO copy
-    // TODO cos
+    it('calculates the inverse tangent of a number', function() {
+      var stack = evaluate('{ 90 atan }');
+      var expectedStack = [Math.atan(90)];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('handles bitshifting ', function() {
+      var stack = evaluate('{ 50 2 bitshift }');
+      var expectedStack = [200];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates the ceiling value', function() {
+      var stack = evaluate('{ 9.9 ceiling }');
+      var expectedStack = [10];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('copies', function() {
+      var stack = evaluate('{ 99 98 2 copy }');
+      var expectedStack = [99, 98, 99, 98];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates the cosine of a number', function() {
+      var stack = evaluate('{ 90 cos }');
+      var expectedStack = [Math.cos(90)];
+      expect(stack).toMatchArray(expectedStack);
+    });
     it('converts to int', function() {
       var stack = evaluate('{ 9.9 cvi }');
       var expectedStack = [9];
@@ -167,24 +187,76 @@ describe('function', function() {
       var expectedStack = [-9];
       expect(stack).toMatchArray(expectedStack);
     });
-    // TODO cvr
-    // TODO div
+    it('converts to real', function() {
+      var stack = evaluate('{ 55.34 cvr }');
+      var expectedStack = [55.34];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('divides', function() {
+      var stack = evaluate('{ 6 5 div }');
+      var expectedStack = [1.2];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('maps division by zero to infinity', function() {
+      var stack = evaluate('{ 6 0 div }');
+      var expectedStack = [Infinity];
+      expect(stack).toMatchArray(expectedStack);
+    });
     it('duplicates', function() {
       var stack = evaluate('{ 99 dup }');
       var expectedStack = [99, 99];
       expect(stack).toMatchArray(expectedStack);
     });
-    // TODO eq
+    it('accepts an equality', function() {
+      var stack = evaluate('{ 9 9 eq }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('rejects an inequality', function() {
+      var stack = evaluate('{ 9 8 eq }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
     it('exchanges', function() {
       var stack = evaluate('{ 44 99 exch }');
       var expectedStack = [99, 44];
       expect(stack).toMatchArray(expectedStack);
     });
-    // TODO exp
-    // TODO false
-    // TODO floor
-    // TODO ge
-    // TODO gt
+    it('handles exponentiation', function() {
+      var stack = evaluate('{ 10 2 exp }');
+      var expectedStack = [100];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('pushes false onto the stack', function() {
+      var stack = evaluate('{ false }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates the floor value', function() {
+      var stack = evaluate('{ 9.9 floor }');
+      var expectedStack = [9];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('handles greater than or equal to', function() {
+      var stack = evaluate('{ 10 9 ge }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('rejects less than for greater than or equal to', function() {
+      var stack = evaluate('{ 8 9 ge }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('handles greater than', function() {
+      var stack = evaluate('{ 10 9 gt }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('rejects less than or equal for greater than', function() {
+      var stack = evaluate('{ 9 9 gt }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
     it('divides to integer', function() {
       var stack = evaluate('{ 2 3 idiv }');
       var expectedStack = [0];
@@ -200,16 +272,86 @@ describe('function', function() {
       var expectedStack = [4, 3, 2, 1, 3];
       expect(stack).toMatchArray(expectedStack);
     });
-    // TODO le
-    // TODO ln
-    // TODO log
-    // TODO lt
-    // TODO mod
-    // TODO mul
-    // TODO ne
-    // TODO neg
-    // TODO not
-    // TODO or
+    it('handles less than or equal to', function() {
+      var stack = evaluate('{ 9 10 le }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('rejects greater than for less than or equal to', function() {
+      var stack = evaluate('{ 10 9 le }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates the natural logarithm', function() {
+      var stack = evaluate('{ 10 ln }');
+      var expectedStack = [Math.log(10)];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates the base 10 logarithm', function() {
+      var stack = evaluate('{ 100 log }');
+      var expectedStack = [2];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('handles less than', function() {
+      var stack = evaluate('{ 9 10 lt }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('rejects greater than or equal to for less than', function() {
+      var stack = evaluate('{ 10 9 lt }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('performs the modulo operation', function() {
+      var stack = evaluate('{ 4 3 mod }');
+      var expectedStack = [1];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('multiplies two numbers (positive result)', function() {
+      var stack = evaluate('{ 9 8 mul }');
+      var expectedStack = [72];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('multiplies two numbers (negative result)', function() {
+      var stack = evaluate('{ 9 -8 mul }');
+      var expectedStack = [-72];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('accepts an inequality', function() {
+      var stack = evaluate('{ 9 8 ne }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('rejects an equality', function() {
+      var stack = evaluate('{ 9 9 ne }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('negates', function() {
+      var stack = evaluate('{ 4.5 neg }');
+      var expectedStack = [-4.5];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('boolean not', function() {
+      var stack = evaluate('{ true not }');
+      var expectedStack = [false];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('bitwise not', function() {
+      var stack = evaluate('{ 12 not }');
+      var expectedStack = [-13];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('boolean or', function() {
+      var stack = evaluate('{ true false or }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('bitwise or', function() {
+      var stack = evaluate('{ 254 1 or }');
+      var expectedStack = [254 | 1];
+      expect(stack).toMatchArray(expectedStack);
+    });
     it('pops stack', function() {
       var stack = evaluate('{ 1 2 pop }');
       var expectedStack = [1];
@@ -225,13 +367,51 @@ describe('function', function() {
       var expectedStack = [3, 2, 2, 1];
       expect(stack).toMatchArray(expectedStack);
     });
-    // TODO round
-    // TODO sin
-    // TODO sqrt
-    // TODO sub
-    // TODO true
-    // TODO truncate
-    // TODO xor
+    it('rounds a number', function() {
+      var stack = evaluate('{ 9.52 round }');
+      var expectedStack = [10];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates the sine of a number', function() {
+      var stack = evaluate('{ 90 sin }');
+      var expectedStack = [Math.sin(90)];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates a square root (integer)', function() {
+      var stack = evaluate('{ 100 sqrt }');
+      var expectedStack = [10];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates a square root (float)', function() {
+      var stack = evaluate('{ 99 sqrt }');
+      var expectedStack = [Math.sqrt(99)];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('subtracts (positive result)', function() {
+      var stack = evaluate('{ 6 4 sub }');
+      var expectedStack = [2];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('subtracts (negative result)', function() {
+      var stack = evaluate('{ 4 6 sub }');
+      var expectedStack = [-2];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('pushes true onto the stack', function() {
+      var stack = evaluate('{ true }');
+      var expectedStack = [true];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('truncates a number', function() {
+      var stack = evaluate('{ 35.004 truncate }');
+      var expectedStack = [35];
+      expect(stack).toMatchArray(expectedStack);
+    });
+    it('calculates an exclusive or value', function() {
+      var stack = evaluate('{ 3 9 xor }');
+      var expectedStack = [10];
+      expect(stack).toMatchArray(expectedStack);
+    });
   });
 });