MAYBE
180.72/59.61	MAYBE
180.72/59.61	
180.72/59.61	Problem:
180.72/59.61	 a(c(x1)) -> a(x1)
180.72/59.61	 d(a(x1)) -> a(c(b(c(d(x1)))))
180.72/59.61	 a(c(b(c(x1)))) -> c(b(c(c(x1))))
180.72/59.61	 c(x1) -> b(a(a(x1)))
180.72/59.61	 d(c(x1)) -> a(c(d(a(x1))))
180.72/59.61	
180.72/59.61	Proof:
180.72/59.61	 Open
180.72/59.62	EOF