MAYBE
111.06/55.40	MAYBE
111.06/55.40	
111.06/55.40	Problem:
111.06/55.40	 a(a(c(x1))) -> b(c(b(a(x1))))
111.06/55.40	 b(x1) -> d(a(x1))
111.06/55.40	 b(a(c(d(x1)))) -> a(a(a(x1)))
111.06/55.40	 c(x1) -> x1
111.06/55.40	 b(x1) -> c(d(x1))
111.06/55.40	
111.06/55.40	Proof:
111.06/55.40	 Open
111.06/55.40	EOF