anchor.diff:  		#'macroexpand-pass
   		#'compiler-macroexpand-pass)
   	#'compile-pass
  +	#'make-post-process-obj
   	#'post-process-ast
  -	#'make-post-process-obj
   	#'filter-used-items
   	#'check-stemcells
   	#'gen-in-arg-strings
  
positive.code:   (make-instance 'post-compile-process :code code :env env
  		 :used-symbol-macros (dedup-used (used-symbol-macros env))
  		 :used-macros (dedup-used (used-macros env))
  		 :used-compiler-macros (dedup-used (used-compiler-macros env))
  		 :ast (node-tree code)))
  
  ;;----------------------------------------------------------------------
  
  
negative.code: 
  ;;----------------------------------------------------------------------
  
  (defun post-process-ast (post-proc-obj)
    (declare (optimize (debug 3) (speed 0)))
    (let ((flow-origin-map (make-hash-table))
  	(val-origin-map (make-hash-table))
  