reserve x,y,z,X for set,
  T for Universe;

theorem Th16:
  for T being non empty 1-sorted, N be constant net of T, i being
  Element of N holds N.i = the_value_of N
proof
  let T be non empty 1-sorted, N be constant net of T, i be Element of N;
  dom the mapping of N = the carrier of N by FUNCT_2:def 1;
  hence N.i = the_value_of the mapping of N by FUNCT_1:def 12
    .= the_value_of N by Def8;
end;
