           @comps.blank.build(),
           @comps.number.build(value: 1)
         )).toEqual false
-    it "accepts against expressions that contain a single blank element", ->
-      expect(
-        @isEqual(
-          @comps.blank.build(),
-          @exp_builder(null)
-        )).toEqual true
-      expect(
-        @isEqual(
-          @exp_builder(null),
-          @comps.blank.build()
-        )).toEqual true
 
   describe "exponentiation", ->
     it "accepts exponents with same base and power", ->

            ])
          )).toEqual false


    describe "comparing an expression against non-expressions", ->
      it "accepts if the first part of the sub expression is equal to what it is comparing against ", ->
        expect(
          @isEqual(
            @comps.expression.build(expression: [
              @comps.number.build(value: 10)
              ]),
            @comps.number.build(value: 10)
          )).toEqual true

      it "rejects if the first part of the sub expression is not equal", ->
        expect(
          @isEqual(
            @comps.expression.build(expression: [
              @comps.number.build(value: 10)
              ]),
            @comps.number.build(value: 11)
          )).toEqual false

  describe "addition", ->
    it "accepts two addition symbols", ->
      expect(

          @comps.number.build(value: 10),
          @comps.number.build(value: 10)
          )).toEqual true

  describe "expression comparison", ->
    it "accepts for empty expressions", ->
