MAYBE
158.83/55.85	MAYBE
158.83/55.85	
158.83/55.85	Problem:
158.83/55.85	 a(a(x1)) -> b(c(c(c(x1))))
158.83/55.85	 b(c(x1)) -> d(d(d(d(x1))))
158.83/55.85	 a(x1) -> d(c(d(x1)))
158.83/55.85	 b(b(x1)) -> c(c(c(x1)))
158.83/55.85	 c(c(x1)) -> d(d(d(x1)))
158.83/55.85	 c(d(d(x1))) -> a(x1)
158.83/55.85	
158.83/55.85	Proof:
158.83/55.85	 Open
158.83/55.85	EOF