This tool easily labels nodes. Here we used it to label
the counter output nodes X3, X2, X1 and X0. To use this tool;
Magic 6.4.4 - Compiled on Tue Oct 11 19:12:59 EDT 1994. CAD_HOME set, pretending that "~cad" is located at "/orca3/cad/sun4cad". Using technology "scmos" Unable to allocate 7 planes in default colormap; making a new one. Extraction style is now "SCN20(VTI)" Warning -- cell counter3 not writable :specialopen netlist Enter labels, one per line, terminated by a blank line: x0 Warning -- cell nor not writable Warning -- cell nand not writable Warning -- cell inv not writable Warning -- cell tff3 not writable Moving label "x0" from space to metal1 in cell counter3. Can't decrement past zero. Moving label "x1" from space to metal1 in cell counter3. Moving label "x2" from space to metal1 in cell counter3.