MAYBE
29.10/10.18	MAYBE
29.10/10.18	
29.10/10.18	Problem:
29.10/10.18	 a(x1) -> x1
29.10/10.18	 a(a(x1)) -> b(x1)
29.10/10.18	 b(c(x1)) -> x1
29.10/10.18	 c(b(x1)) -> a(b(c(c(x1))))
29.10/10.18	
29.10/10.18	Proof:
29.10/10.18	 Open
29.10/10.19	EOF