bug#38392: zap-up-to-char should appear in "Deletion and Killing" Emacs info section and "Command Index"

[Drew Adams]

> I suppose you’re saying that exactly two ‘inclusivities’ suffice: ‘up 
> to/until’ and 'through' in your case, which makes complete sense.

I wasn't speaking to what might suffice.  I was just
pointing out that we use `up-to' for zapping and `until' for searching - and we 
mean the same thing by them.  And I mentioned `through' as a possible name for 
including the final char. 

> I have found that both 'up to' and 'until' are still ambiguous, for instance 
> when trying to agree on a date with someone. This ambiguity might carry over 
> to the Emacs world, where a user might not know that there is another 
> distinct inclusivity called 'through'. 'up to' and 'until' can mean either 
> 'inclusive' or 'exclusive', this seemingly depending on the phase of the 
> Moon. I still use the words 'inclusive' and 'exclusive' to confirm. I hope 
> that at least programmers don't find that silly. Of course, there is an 
> existing precedent of 'up to', 'until', 'through' and 'to'.

Yes, the terms are ambiguous.  If we use consistent
names and the doc is clear then I don't think there's
a problem in practice.  But yes, in conversation,
and particularly with dates/times, people can need
to discuss a bit to be sure to be on the same page.

> Regardless of the naming, wouldn’t an inclusivity modifier over the set of 
> two inclusivities be a nice thing to have?

No idea.  Modifier where?  Here we're talking about
function names.  I don't think we need to or should
add such a thing to the names.