reserve T for non empty Abelian
  add-associative right_zeroed right_complementable RLSStruct,
  X,Y,Z,B,C,B1,B2 for Subset of T,
  x,y,p for Point of T;
reserve t,s,r1 for Real;
reserve n for Element of NAT;
reserve X,Y,B1,B2 for Subset of TOP-REAL n;
reserve x,y for Point of TOP-REAL n;

theorem Th61:
  X c= Y implies t(.)X c= t(.)Y
proof
  assume
A1: X c= Y;
  let x be object;
  assume x in t(.)X;
  then ex a being Point of TOP-REAL n st x = t*a & a in X;
  hence thesis by A1;
end;
