MAYBE
28.78/10.18	MAYBE
28.78/10.18	
28.78/10.18	Problem:
28.78/10.18	 a(x1) -> x1
28.78/10.18	 a(b(x1)) -> b(a(c(b(a(x1)))))
28.78/10.18	 b(x1) -> x1
28.78/10.18	 c(c(c(x1))) -> x1
28.78/10.18	
28.78/10.18	Proof:
28.78/10.18	 Open
28.78/10.19	EOF