van Vliet use of backquote (and backslash)

[Jose E. Marchesi]

Two problems:

1) `plus i times' is a monad. As such, it has to be treated like a
   symbol and thus we cannot use the letter `i' for it, because then the
   tag `min' would be interpreteed as tag `m', symbol `i' tag `n'.  So
   we need a symbol for it, as similar as possible as the one proposed
   by the reference language in 9.4.1.c.

2) In rule 812h:

   h) times ten to the power choice{g} :
     times ten to the power symbol{94b} ; letter e symbol{94a}.

   So both the letter `e' and some `times ten to the power symbol' are
   allowed in real denotations.  I suppose we could say that the
   representation of `times ten to the power symbol' is also "e".  The
   scanner already recognizes "e" for this purpose.

> Hello All,
>
> This thread is interesting and I am totally ill-equipped to comment on
> the Vliet aspects.
>
> That said, from a user perspective, the use of "e" in 10.0e3 is so
> ubiquitous that any other denotations would be confusing.  So, seems
> wasteful to use a precious "\" for that.
>
> Regarding 4.7i3.2,  I have never seen it.  But I LOVE IT!  Crisp,
> clean, concise, and without any visual clutter.
>
> Thanks! /James
>
>
>
> On Mon, Feb 9, 2026 at 5:14 AM chris hermansen <clhermansen@gmail.com> wrote:
>>
>> Jose and list,
>>
>> On Sat, Feb 7, 2026 at 3:51 PM Jose E. Marchesi <jemarch@gnu.org> wrote:
>>>
>>>
>>> > Good evening all
>>> >
>>> > I noticed tonight while poring through van Vliet's transput code that he
>>> > appropriates the backquote as "plus_i_times", as part of his defining sets
>>> > of characters to be used in transput formatting conversion:
>>> >
>>> > CharBag {ℵ₀} radix10digit = STRINGTOBAG "0123456789",
>>> >         {ℵ₀} radix_2digit = STRINGTOBAG "01",
>>> >         {ℵ₀} radix_4digit = STRINGTOBAG "0123",
>>> >         {ℵ₀} radix_8digit = STRINGTOBAG "01234567",
>>> >         {ℵ₀} radix16digit = STRINGTOBAG "0123456789abcedf",
>>> >         {ℵ₀} time_ten_to_the_power = STRINGTOBAG "\eE",
>>> >         {ℵ₀} flipflop               = STRINGTOBAG (flip + flop),
>>> >         {ℵ₀} plus_i_times           = STRINGTOBAG "`iI",
>>> >         {ℵ₀} signspace              = STRINGTOBAG "+- ",
>>> >         {ℵ₀} plusminus              = STRINGTOBAG "+-",
>>> >         {ℵ₀} point                  = STRINGTOBAG string("."),
>>> >         {ℵ₀} xylpkq                 = STRINGTOBAG "xylpkq";
>>> >
>>> > His CharBag type above is like a Java HashSet<Character> and the
>>> > STRINGTOBAG operator converts a string to a CharBag instance.
>>> >
>>> > This is the only place it appears in the code but of course the name
>>> > plus_i_times appears in a few places...
>>> >
>>> > I'm thinking that, given the earlier discussion about whether or not
>>> > backquote could be usurped for some other use, maybe better to nip this one
>>> > in the bud...
>>>
>>> At the end we are following Hansen's recommendation and using apostrophe
>>> for the brief form of OF.
>>>
>>> If/when we support left to right selection, it will most certainly be
>>> using the dot character, not the backquote.
>>>
>>> So the backquote is free... do we want to use it for plus_i_times?
>>> Thats the question :)
>>>
>>> >
>>> > The eagle-eyed reader who has yet to fall asleep reading this will also
>>> > note that van Vliet has proposed using the backslash as an alternative for
>>> > time_ten_to_the_power... which maybe also should be discouraged.
>>>
>>> I have wondered about that one as well.  At the moment backslash is also
>>> free, but do we want to spend it on this?
>>>
>>> What are common representation for plus_i_times and
>>> time_ten_to_the_power?  I mean generally.
>>
>>
>> I haven't had a lot of luck with my "favourite" search engine as to
>> finding new denotations for times ten to the power of nor plus i
>> times.  But I did pick this out of the RR:
>>
>> Wherever (in the transput declarations) the representation ₁₀ (\, ⊥)
>> [subscript 10, backslash, tack) occurs within a
>> <bold>character-denotation</bold> or <bold>string-denotation</bold>,
>> it is to be interpreted as the representation of the
>> <bold>string-item</bold> (8.1.4.1.b) used to indicate "times ten to
>> the power" (an alternative form {, if any.} of "times ten to the
>> power", "plus i times") on external media. {Clearly, these
>> representations have been chosen because of their similarity to
>> those of the <bold>times-ten-to-the-power-symbol</bold> (9.4.1.b)
>> and the <bold>plus-i-times-symbol</bold> (9.4.1.c), but, on media on
>> which these characters are not available, other
>> <bold>string-items</bold> must be chosen (and the
>> <bold>letter-e-symbol</bold> and the <bold>letter-i-symbol are
>> obvious candidates</bold>).}
>>
>>
>> I have tried to be very careful above in using <bold>...</bold> to
>> bracket formal grammar terms and I have used the Unicode characters
>> I believe represent the graphical representations of "times ten to
>> the power" and "plus i times".
>>
>> In my opinion, we should at least consider 10.0e3 and 4.7i3.2 as
>> respective denotations, given the stated interest in avoiding
>> characters not available without using the Compose key or other
>> artifices required to select "non-keyboardable" Unicode characters.
>>
>> I dislike the idea of "wasting" \ for "times ten to the power" and `
>> for "plus i times" as neither character is especially evocative of
>> the proposed meaning.  Moreover a casual reader would more likely be
>> familiar with at least 10.0e3 as meaning "ten to the power of 3" and
>> could probably intuit 4.7i3.2 as 4.7 + 3.2i if s/he knew anything
>> about complex numbers.
>>
>> Put another way - if there is any customary use of backslash as
>> "times ten to the power" and ` as "plus i times", I at least have
>> yet to discover it.
>> --
>> Chris Hermansen · clhermansen "at" gmail "dot" com
>>
>> C'est ma façon de parler.