anchor.diff:  	(car successors)
   	(sicl-mir:make-assignment-instruction
   	 (sicl-mir:make-immediate-input (sicl-ast:value ast))
  +	 (car results)
  +	 (car successors)))))
  +
  +;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  +;;;
  +;;; Compile a CONSTANT-AST.
  +;;;
  +
  +(defmethod compile-ast ((ast sicl-ast:constant-ast) context)
  +  (with-accessors ((results results)
  +		   (successors successors))
  +      context
  +    (unless (and (listp results)
  +		 (= (length results) 1)
  +		 (= (length successors) 1))
  +      (error "Invalid results for constant."))
  +    (if (eq ast (car results))
  +	(car successors)
  +	(sicl-mir:make-assignment-instruction
  +	 (sicl-mir:make-constant-input (sicl-ast:value ast))
   	 (car results)
   	 (car successors)))))
   
  
positive.code: 
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Compile a IMMEDATE-AST.
  ;;;
  
  (defmethod compile-ast ((ast sicl-ast:immediate-ast) context)
  
negative.code: (defun make-temp (argument)
    (cond ((typep argument 'sicl-env:lexical-location)
  	 argument)
  	((typep argument 'sicl-ast:constant-ast)
  	 (sicl-mir:make-constant-input (sicl-ast:value argument)))
  	((typep argument 'sicl-ast:immediate-ast)
  	 (sicl-mir:make-immediate-input (sicl-ast:value argument)))
  	((typep argument 'sicl-ast:load-time-value-ast)
  