MAYBE
236.01/59.79	MAYBE
236.01/59.79	
236.01/59.79	Problem:
236.01/59.79	 a(l(x1)) -> l(a(x1))
236.01/59.79	 r(a(a(x1))) -> a(a(r(x1)))
236.01/59.79	 b(l(x1)) -> b(a(r(x1)))
236.01/59.79	 r(b(x1)) -> l(b(x1))
236.01/59.79	
236.01/59.79	Proof:
236.01/59.79	 Open
236.01/59.80	EOF