MAYBE
50.13/20.12	MAYBE
50.13/20.12	
50.13/20.12	Problem:
50.13/20.12	 a(a(b(b(x1)))) -> b(b(b(a(a(a(x1))))))
50.13/20.12	 a(x1) -> x1
50.13/20.12	
50.13/20.12	Proof:
50.13/20.12	 Open
50.13/20.12	EOF