MAYBE
40.99/11.13	MAYBE
40.99/11.13	
40.99/11.13	Problem:
40.99/11.13	 a(x1) -> b(b(c(x1)))
40.99/11.13	 c(a(b(x1))) -> a(a(c(x1)))
40.99/11.13	 c(b(x1)) -> x1
40.99/11.13	
40.99/11.13	Proof:
40.99/11.13	 Open
40.99/11.14	EOF