-- RELALGP1proof Derivation of All x y:(((Q*R)<=S)(x,y)) <==> All x y:(((T(Q)*C(S))<=C(R))(x,y)) Narrowing the preceding formula (7 steps) leads to All x y z:(Q(x,z) & R(z,y) ==> S(x,y)) <==> All x y z0:(Q(z0,x) & notS(z0,y) ==> notR(x,y)) The reducts have been simplified. Shifting subformulas at positions [1,0,0,1],[1,0,1] of the preceding formula leads to All x y z:(Q(x,z) & R(z,y) ==> S(x,y)) <==> All x y z0:(R(x,y) & Q(z0,x) ==> S(z0,y)) Simplifying the preceding formula (2 steps) leads to True Number of proof steps: 3 Solutions: True