On Wed, Jan 28, 2026 at 01:07:30PM -0600, G. Branden Robinson wrote:

At 2026-01-28T17:52:15+0100, наб wrote:

quoted

You wrote it confusingly (if I wrote it like that it'd be on purpose;
I doubt that was your intent but that's how it reads), so I
isomorphised your program into third normal form:

A) I believe the "correct" locution would be "isomorphed", by analogy
   with "the party magic-user polymorphed the gate guard into a toad".

I got there from "applied isomorphisms" so I analysed it as "isomorphism-ised";
if you morph stuff unchangingly instead, "iso-morphed" makes more sense.

(Isomorphed also reads preferentially reflexive to me,
 but I see both in literature with a preference for isomorphed,
 both used reflexively and not.)

B) (While the foregoing discusses GNU Bash specifically, I have
   read--but not seen a proof, and can't promise that I'd understand a
   proof if I saw one--that POSIX shell is undecidable as well, the
   "alias" feature being a sufficient condition to produce thus.)

If, AIUI, "undecidable" in this case means "the parser depends on the
execution of the program being parsed", then alias is sufficient
do ensure this property, but I think it's the only feature that
lets you inject macros into the parser,
or otherwise interact with it directly like this.

Best,