MAYBE
158.45/55.98	MAYBE
158.45/55.98	
158.45/55.98	Problem:
158.45/55.98	 a(a(x1)) -> b(b(b(x1)))
158.45/55.98	 a(x1) -> d(c(d(x1)))
158.45/55.98	 b(b(b(x1))) -> a(f(x1))
158.45/55.98	 b(b(x1)) -> c(c(c(x1)))
158.45/55.98	 c(c(x1)) -> d(d(d(x1)))
158.45/55.98	 c(d(d(x1))) -> f(x1)
158.45/55.98	 f(f(x1)) -> f(a(x1))
158.45/55.98	
158.45/55.98	Proof:
158.45/55.98	 Open
158.45/55.98	EOF