MAYBE
0.19/0.20	MAYBE
0.19/0.20	
0.19/0.20	Problem:
0.19/0.20	 active(p(0())) -> mark(0())
0.19/0.20	 active(p(s(X))) -> mark(X)
0.19/0.20	 active(leq(0(),Y)) -> mark(true())
0.19/0.20	 active(leq(s(X),0())) -> mark(false())
0.19/0.20	 active(leq(s(X),s(Y))) -> mark(leq(X,Y))
0.19/0.20	 active(if(true(),X,Y)) -> mark(X)
0.19/0.20	 active(if(false(),X,Y)) -> mark(Y)
0.19/0.20	 active(diff(X,Y)) -> mark(if(leq(X,Y),0(),s(diff(p(X),Y))))
0.19/0.20	 active(p(X)) -> p(active(X))
0.19/0.20	 active(s(X)) -> s(active(X))
0.19/0.20	 active(leq(X1,X2)) -> leq(active(X1),X2)
0.19/0.20	 active(leq(X1,X2)) -> leq(X1,active(X2))
0.19/0.20	 active(if(X1,X2,X3)) -> if(active(X1),X2,X3)
0.19/0.20	 active(diff(X1,X2)) -> diff(active(X1),X2)
0.19/0.20	 active(diff(X1,X2)) -> diff(X1,active(X2))
0.19/0.20	 p(mark(X)) -> mark(p(X))
0.19/0.20	 s(mark(X)) -> mark(s(X))
0.19/0.20	 leq(mark(X1),X2) -> mark(leq(X1,X2))
0.19/0.20	 leq(X1,mark(X2)) -> mark(leq(X1,X2))
0.19/0.20	 if(mark(X1),X2,X3) -> mark(if(X1,X2,X3))
0.19/0.20	 diff(mark(X1),X2) -> mark(diff(X1,X2))
0.19/0.20	 diff(X1,mark(X2)) -> mark(diff(X1,X2))
0.19/0.20	 proper(p(X)) -> p(proper(X))
0.19/0.20	 proper(0()) -> ok(0())
0.19/0.20	 proper(s(X)) -> s(proper(X))
0.19/0.20	 proper(leq(X1,X2)) -> leq(proper(X1),proper(X2))
0.19/0.20	 proper(true()) -> ok(true())
0.19/0.20	 proper(false()) -> ok(false())
0.19/0.20	 proper(if(X1,X2,X3)) -> if(proper(X1),proper(X2),proper(X3))
0.19/0.20	 proper(diff(X1,X2)) -> diff(proper(X1),proper(X2))
0.19/0.20	 p(ok(X)) -> ok(p(X))
0.19/0.20	 s(ok(X)) -> ok(s(X))
0.19/0.20	 leq(ok(X1),ok(X2)) -> ok(leq(X1,X2))
0.19/0.20	 if(ok(X1),ok(X2),ok(X3)) -> ok(if(X1,X2,X3))
0.19/0.20	 diff(ok(X1),ok(X2)) -> ok(diff(X1,X2))
0.19/0.20	 top(mark(X)) -> top(proper(X))
0.19/0.20	 top(ok(X)) -> top(active(X))
0.19/0.20	
0.19/0.20	Proof:
0.19/0.20	 Open
0.19/0.20	EOF