
theorem Th2:
  for S1,S2 being non empty ManySortedSign st S1 tolerates S2 &
InnerVertices S1 is Relation & InnerVertices S2 is Relation holds InnerVertices
  (S1+*S2) is Relation
proof
  let S1, S2 be non empty ManySortedSign;
  assume
A1: S1 tolerates S2;
  assume InnerVertices S1 is Relation & InnerVertices S2 is Relation;
  then reconsider R1 = InnerVertices S1, R2 = InnerVertices S2 as Relation;
  R1 \/ R2 is Relation;
  hence thesis by A1,CIRCCOMB:11;
end;
