perm filename BLOCK2[S86,JMC] blob sn#819578 filedate 1986-06-18 generic text, type C, neo UTF8
COMMENT āŠ—   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	on(X,Y,r(m(X,Y),S)) :- \+ ab(X,Y,S).
C00003 ENDMK
CāŠ—;
on(X,Y,r(m(X,Y),S)) :- \+ ab(X,Y,S).
ab(X,Y,S) :- on(Z,X,S).
on(X,Y,r(E,S)) :- on(X,Y,S),\+ ab1(X,Y,E,S).
ab1(X,Y,m(X,Z),S).
%on(X,Y,S) :- on(X,Y,r(E,S)),\+ ab1(X,Y,E,S).