theorem Th7:
  x in rng RestrictSub(x,All(x,p),Sub) implies S_Bound([All(x,p),
  Sub]) = x.upVar(RestrictSub(x,All(x,p),Sub),p)
proof
  set finSub = RestrictSub(x,All(x,p),Sub);
  set S = [All(x,p),Sub];
  assume
A1: x in rng finSub;
  reconsider q = S`1 as Element of CQC-WFF(Al);
A2: S`2 = Sub;
  bound_in q = x & the_scope_of q = p by QC_LANG2:7;
  hence thesis by A1,A2,SUBSTUT1:def 36;
end;
