     @math = ttm.lib.math.math_lib.build()
     builder_lib = ttm.require('lib/math/build_expression_from_javascript_object')
     @exp = @math.object_to_expression.buildExpressionFunction()
-
+    @expect_evaluation = expect_evaluation
   it "evaluates a simple addition", ->
     exp = @exp(2, '+', 7)
     results = @evaluation.build(exp).resultingExpression()

    new_exp = @evaluation.build(exp).resultingExpression()
    expect(new_exp).toBeAnEqualExpressionTo @exp(60)


#= require lib/math/expression_evaluation

expect_evaluation = (orig, goal)->
  exp = @exp(orig)
  new_exp = @evaluation.build(exp).resultingExpression()
  expect(new_exp).toBeAnEqualExpressionTo @exp(goal)




describe "math expression evaluation", ->
