[From Bruce Abbott (960826.1130 EST)]

Rick Marken (960826.0810) --

Bruce Abbott (960825.1120 EST)

why not just use "model" (without the modifier) to mean "model" as
you've always understood it to mean. If anyone wants to refer to the
properties of a system that take account of the properties of the
environment as a kind of model of the environment, they can add the
modifier "implicit." In the context where both are being talked about,
the usual kind of model can be identified as "explicit" if necessary to
preserve clarity, but otherwise this would not be necessary. No babel,
no tower, no confusion.

Since "implicit", like "model", already has an agreed on meaning that
is inconsistent with the meaning you intend when you say "implicit
model", why not use a word that already has the meaning you intend, such
as "not".

I do not mean "implicit" to mean "not." I mean "involved in the nature or
being of something, though not shown," which is one of the definitions of
"implicit" given in Webster's. I'm bored by this silly argument; as usual
the debate has been shifted from the issue at hand (whether by their design,
control systems must take account of certain properties of the environment
with which they must deal) to a silly debate about semantics, and whether
words should be used in a certain way. Words are symbols whose purpose is
to communicate meaning; I have explained what meaning I attach to those
words; therefore you know (or should know) my meaning, so let's discuss what
I mean rather than the words I use. The debate about words is keeping us
from discussing the real issue. The word-debate is, well, just babel.