197.15/50.21	MAYBE
197.15/50.21	
197.15/50.21	Problem:
197.15/50.21	 a(b(a(b(x1)))) -> a(a(b(b(x1))))
197.15/50.21	 b(b(b(b(x1)))) -> b(b(b(a(x1))))
197.15/50.21	 a(a(a(a(x1)))) -> b(a(b(a(x1))))
197.15/50.21	
197.15/50.21	Proof:
197.15/50.21	 Open
197.15/50.22	EOF