MAYBE
27.14/10.18	MAYBE
27.14/10.18	
27.14/10.18	Problem:
27.14/10.18	 a(x1) -> x1
27.14/10.18	 a(b(x1)) -> c(b(c(b(x1))))
27.14/10.18	 b(x1) -> a(a(x1))
27.14/10.18	 c(c(x1)) -> x1
27.14/10.18	
27.14/10.18	Proof:
27.14/10.18	 Open
27.14/10.19	EOF