BX vs. BC (everybody relax, please)

[Eric Van Tassel 101233.342@xxxxxxxx]

I like to think, in my sad little life, that I have a few real friends, and
some of them are on this List. It saddens me when my friends start
bickering.

Here's my two cents' worth on BX/BC. When I first encountered BX/Q2 (in the
Xy4 Startup file when I switched from Xy3) I was just puzzled; as was my
wont, in the years before I encountered this List, I suppressed my
puzzlement, shrugged and thought no more about it, leaving BX/Q2 alone in
existing files but not using it myself.

Then I found I had a problem: I wanted to do a simple global search/replace
(in which a caret ASCII 94 would change to a hard space ASCII 32) and it
just wouldn't work. Someone on this list (sorry, I can't remember who) told
me to try BX/Q2, in conjunction with "/t" and parentheses.

Specifically,
        BC cia .[94].[32]. XC
just left the 94s unaltered in the file;
        BX cia .[94].[32]. Q2
either didn't work or actually crashed (sorry, I can't remember which); but
        BX (cia/t .[94].[32].) Q2
did work, and worked just fine.

I have no idea what "/t" means, or why the third lemma above works and the
second one doesn't. Since then, I continue to use BC/XC as my default (if
only out of habit left over from Xy3); whenever I have a BC cia ... XC
command that gives me trouble, my first recourse is to change it to BX
(cia/t ...) Q2 and see if that helps. Often it does.

If someone can explain *why* the difference, I'll be fascinated. But the
why of it matters less than the fact that it works; and the why of it also
matters less than the fact that I have this resource in my repertoire only
because someone on this List took the time (unpaid) to tell me about it.

Cheers
Eric Van Tassel