Input TRS:
    1: f(el(x),y) -> f(x,el(y))
   e1: f(x,y) ->= f(l(x),y)	[relative]
   e2: f(x,y) ->= f(x,r(y))	[relative]
   e3: l(el(x)) ->= el(l(x))	[relative]
   e4: el(r(x)) ->= r(el(x))	[relative]
Number of Rules: 1
Direct POLO(Sum) ...Direct Mat2b ... removes: 1
	I(r) = x1 + [0;1]
	I(l) = x1
	I(f) = [1,1;0,1] * x1 + [1,0;0,0] * x2
	I(el) = x1 + [1;1]
Number of Rules: 0