anchor.diff:     +retrieval>
         isa        count-order
         first      =count
  -)+)
  +
  +(goal-focus second-goal)
  +)
  
positive.code:       first      =num1
  )
  
  (p terminate-addition
     =goal>
        isa         add
        count       =num
        arg2        =num
        sum         =answer
  
negative.code: (define-model addition
  
  (chunk-type count-order first second)
  (chunk-type add arg1 arg2 sum count)
  
  (add-dm
     (a ISA count-order first 0 second 1)
     (b ISA count-order first 1 second 2)
     (c ISA count-order first 2 second 3)
     (d ISA count-order first 3 second 4)
     (e ISA count-order first 4 second 5)
     (f ISA count-order first 5 second 6)
     (g ISA count-order first 6 second 7)
     (h ISA count-order first 7 second 8)
     (i ISA count-order first 8 second 9)
     (j ISA count-order first 9 second 10)
     (second-goal ISA add arg1 5 arg2 2))
  
  (P initialize-addition
     =goal>
        ISA         add
        arg1        =num1
        arg2        =num2
        sum         nil
  