MAYBE
42.41/11.44	MAYBE
42.41/11.44	
42.41/11.44	Problem:
42.41/11.44	 a(b(x1)) -> x1
42.41/11.44	 a(c(x1)) -> b(c(c(a(x1))))
42.41/11.44	 b(c(x1)) -> a(b(x1))
42.41/11.44	
42.41/11.44	Proof:
42.41/11.44	 Open
42.41/11.44	EOF