YES Problem: strict: o(lambda(x),y) -> lambda(o(x,d(1(),o(y,p())))) o(d(x,y),z) -> d(o(x,z),o(y,z)) o(o(x,y),z) -> o(x,o(y,z)) lambda(x) -> x o(x,y) -> x o(x,y) -> y d(x,y) -> x d(x,y) -> y weak: o(x,y) -> d(x,y) o(x,y) -> d(y,x) Proof: RT Transformation Processor: o(lambda(x),y) -> lambda(o(x,d(1(),o(y,p())))) o(d(x,y),z) -> d(o(x,z),o(y,z)) o(o(x,y),z) -> o(x,o(y,z)) lambda(x) -> x o(x,y) -> x o(x,y) -> y d(x,y) -> x d(x,y) -> y o(x,y) -> d(x,y) o(x,y) -> d(y,x) WPO Processor: algebra: MSum weight function: w0 = 0 w(lambda) = 6 w(d) = w(p) = w(1) = w(o) = 0 status function: st(d) = [0, 1] st(p) = st(1) = [] st(o) = [0, 1] st(lambda) = [0] subterm penalty function: sp(lambda, 0) = 4 sp(d, 1) = sp(d, 0) = sp(o, 1) = sp(o, 0) = 0 subterm coefficient function: sc(d, 1) = sc(d, 0) = sc(o, 1) = sc(o, 0) = sc(lambda, 0) = 1 weight status function: ws(1) = ws(o) = pol ws(d) = ws(p) = ws(lambda) = max precedence: o > d ~ p ~ 1 ~ lambda problem: Qed