reserve R for Ring, S for R-monomorphic Ring,
        K for Field, F for K-monomorphic Field,
        T for K-monomorphic comRing;

theorem Th16:
   K,F are_disjoint implies
   ex E being Field st E,F are_isomorphic & K is Subfield of E
   proof
     assume AS: K,F are_disjoint;
     set f = the Monomorphism of K,F;
     reconsider E = embField f as Field by AS,Th6,Th8,Th9,Th7,Th10;
     take E;
     thus thesis by AS,Th14,Th15;
   end;
