MAYBE
251.67/63.91	MAYBE
251.67/63.92	
251.67/63.92	Problem:
251.67/63.92	 a__zeros() -> cons(0(),zeros())
251.67/63.92	 a__U11(tt(),L) -> a__U12(tt(),L)
251.67/63.92	 a__U12(tt(),L) -> s(a__length(mark(L)))
251.67/63.92	 a__length(nil()) -> 0()
251.67/63.92	 a__length(cons(N,L)) -> a__U11(tt(),L)
251.67/63.92	 mark(zeros()) -> a__zeros()
251.67/63.92	 mark(U11(X1,X2)) -> a__U11(mark(X1),X2)
251.67/63.92	 mark(U12(X1,X2)) -> a__U12(mark(X1),X2)
251.67/63.92	 mark(length(X)) -> a__length(mark(X))
251.67/63.92	 mark(cons(X1,X2)) -> cons(mark(X1),X2)
251.67/63.92	 mark(0()) -> 0()
251.67/63.92	 mark(tt()) -> tt()
251.67/63.92	 mark(s(X)) -> s(mark(X))
251.67/63.92	 mark(nil()) -> nil()
251.67/63.92	 a__zeros() -> zeros()
251.67/63.92	 a__U11(X1,X2) -> U11(X1,X2)
251.67/63.92	 a__U12(X1,X2) -> U12(X1,X2)
251.67/63.92	 a__length(X) -> length(X)
251.67/63.92	
251.67/63.92	Proof:
251.67/63.92	 Open
251.67/63.92	EOF