perm filename RESIDU.LSP[F76,JMC]1 blob sn#254282 filedate 1976-12-16 generic text, type C, neo UTF8
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C00001 00001
C00002 00002
C00004 ENDMK
CāŠ—;


(DE RESIDUE (X Y) 
       (COND ((EQ X Y) T)
	     ((ATOM X)
	      (COND ((ATOM Y) NIL)
		    (T ((LAMBDA (W) (COND ((EQ X (CAR W))
					   (CONS 'R (CDR W)))
					  (T NIL)))
			(GOPHER Y)))))
	     ((ATOM Y)
	      ((LAMBDA (W) 
		       (COND ((EQ Y (CAR W)) (CONS 'L (CDR W)))
			     (T NIL)))
	       (GOPHER X)))
	     (T ((LAMBDA (W) 
			 (COND ((NULL W) NIL)
			       ((EQ W T) (RESIDUE (CDR X) (CDR Y)))
			       ((EQ (CAR W) 'L)
				(RESIDUE (CONS (CDR W) (CDR X))
					 (CDR Y)))
			       (T (RESIDUE (CDR X)
					   (CONS (CDR W) (CDR Y))))))
		 (RESIDUE (CAR X) (CAR Y)))))) 

(DE GOPHER (U) 
       (COND ((ATOM (CAR U)) U)
	     (T (GOPHER (CONS (CAAR U) (CONS (CDAR U) (CDR U))))))) 


(DE SAMEFRINGE (X Y) (EQ (RESIDUE X Y) T))