213.64/50.21	MAYBE
213.64/50.21	
213.64/50.21	Problem:
213.64/50.21	 a(a(a(x1))) -> b(x1)
213.64/50.21	 b(c(x1)) -> c(c(a(a(a(a(x1))))))
213.64/50.21	
213.64/50.21	Proof:
213.64/50.21	 Open
213.64/50.21	EOF