YES ---- CR(R) ---- Development Closedness Theorem [van Oostrom, TCS 1994]. R: F(G(x,A(),B())) -> x G(F(H(C(),D())),x,y) -> H(K1(x),K2(y)) K1(A()) -> C() K2(B()) -> D() CP(R): F(H(K1(A()),K2(B()))) -> F(H(C(),D()))