anchor.diff:  
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
  -;;; LIR instruction MEMREF2-INSTRUCTION
  +;;; MIR instruction MEMREF2-INSTRUCTION
   ;;;
   ;;; This instruction loads a memory location.  It takes a two inputs.
   ;;; The first input contains the base address of the datum to load.
  
positive.code: 
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; LIR instruction UNSIGNED-ADD-INSTRUCTION
  
  (defclass unsigned-add-instruction (instruction two-successors-mixin)
    ())
  
negative.code: 
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; MIR instruction EQUAL-INSTRUCTION
  
  (defclass signed-equal-instruction (instruction two-successors-mixin)
    ())
  