reserve L for Lattice;
reserve X,Y,Z,V for Element of L;
reserve L for D_Lattice;
reserve X,Y,Z for Element of L;
reserve L for 0_Lattice;
reserve X,Y,Z for Element of L;
reserve L for B_Lattice;
reserve X,Y,Z,V for Element of L;

theorem Th47:
  X \ Bottom L = X
proof
  X \ Bottom L = X "/\" Top L by LATTICE4:30
    .= X;
  hence thesis;
end;
