Art wrote:
"It is very simple and it is related solely to antenna computor programs
that are used presently around the World,"

Supposing that Art means: Does NEC-2 model wires as solid or hollow?

It makes no difference. Skin effect makes a hollow wire appear to be
solid.

Computer programs successfully predict antenna performance so they are
in demand the world over as Art noted. They make the tedious easy.

Best regards, Richard Harrison, KB5WZI