theorem Th10:
  Constants(OU0) c= OSConstants(OU0)
proof
  let i be object;
  assume i in the carrier of S1;
  then reconsider s = i as SortSymbol of S1;
  (Constants(OU0)).s = Constants(OU0,s) & (OSConstants(OU0)).s =
  OSConstants( OU0,s) by Def5,MSUALG_2:def 4;
  hence thesis by Th6;
end;
