(DEFPROP TRYASSIGN 
 (LAMBDA N
  ((LAMBDA(VARS VAR PAT MALIST PALISTV VARSALLOWED RS)
    (COND (VARS
	   (COND
	    ((OR VARSALLOWED (NOT (HASMUSTASSIGNS VARS)))
	     (COND ((HASVARS VARS))
		   (T
		    ((LAMBDA (VAL) (PROG NIL (MSET VAR VAL MALIST) (RETURN (SATISFY RS MALIST))))
		     (VARSUBST PAT (CDR PALISTV))))))))
	  (T (MSET VAR PAT MALIST) (SATISFY RS MALIST))))
   (FINDVARS (ARG 2) (ARG 4))
   (ARG 1)
   (ARG 2)
   (ARG 3)
   (ARG 4)
   (ARG 5)
   (ARG 6))) 
EXPR)