reserve x,y for object;
reserve S for non void non empty ManySortedSign,
  o for OperSymbol of S,
  U0,U1, U2 for MSAlgebra over S;

theorem
  for S be non void all-with_const_op non empty ManySortedSign, U0 be
non-empty MSAlgebra over S, U1 be non-empty MSSubAlgebra of U0 holds Constants(
  U0) is non-empty MSSubset of U1 by Th10;
