theorem Th115:
       L is subst-correct vf-qc-correct &
  A\impB in G implies (\for(x,A)\imp\for(x,B)) in G
  proof
    assume
A1: L is subst-correct vf-qc-correct;
    assume A\impB in G;
    then
A2: \for(x,A\impB) in G by Def39;
    \for(x,A\impB)\imp(\for(x,A)\imp\for(x,B)) in G by A1,Th109;
    hence thesis by A2,Def38;
  end;
