Hello Stavros,
> In what cases do you think it would be helpful to the
> user to define op(1) as false rather than an error?
As a general policy, I would like to see errors triggered in the
most limited circumstances possible. This is part of the still more
general policy, "Do not assume there is someone at the console".
Coming to a dead halt because the argument a in something like op(a) = "+"
is an atom is needlessly heavy-handed.
However, nobody else seems to be interested in this particular proposal,
so I'm going to drop it here. Thanks for your comments.
Robert