let L1, L2, L3 be complete LATTICE; for d1 being sups-preserving Function of L1,L2
for d2 being sups-preserving Function of L2,L3 holds UpperAdj (d2 * d1) = (UpperAdj d1) * (UpperAdj d2)
let d1 be sups-preserving Function of L1,L2; for d2 being sups-preserving Function of L2,L3 holds UpperAdj (d2 * d1) = (UpperAdj d1) * (UpperAdj d2)
let d2 be sups-preserving Function of L2,L3; UpperAdj (d2 * d1) = (UpperAdj d1) * (UpperAdj d2)
A1:
[(UpperAdj d1),d1] is Galois
by Def2;
[(UpperAdj d2),d2] is Galois
by Def2;
then A2:
[((UpperAdj d1) * (UpperAdj d2)),(d2 * d1)] is Galois
by A1, WAYBEL15:5;
d2 * d1 is sups-preserving
by WAYBEL20:27;
hence
UpperAdj (d2 * d1) = (UpperAdj d1) * (UpperAdj d2)
by A2, Def2; verum