           @root_converter
           @variable_converter
           @fraction_converter
+          @fn_converter
           ]
 
       process: (js_object)->

          @processor,
          @component_builder)

        @string_literal_converter = _FromStringLiteralObject.build(@component_builder,{
          "+": "build_addition"
          "-": "build_subtraction"

          numerator: numerator
          denominator: denominator
        )
    class_mixer _FromFractionObject

    class _FromFnObject
      initialize: (@converter, @fn_builder)->
      isType: (js_object)->
        js_object['fn'] instanceof Array
      convert: (js_object)->
        name = js_object['fn'][0]
        argument = convert_implicit_subexp(js_object['fn'][1], @converter)

        @fn_builder.build_fn(
          name: name
          argument: argument
        )
    class_mixer _FromFnObject

    class _FromStringLiteralObject
      initialize: (@converter, @literal_mappings)->
