van Vliet use of backquote (and backslash)

[Jose E. Marchesi]

> Hello Jose,
>
> Thanks for this information.  I had been assuming that since the "e"
> would only ever be placed between two numbers, such as:
>
> a)  1.234e4
> b)  5.67e-8
>
> Then it might be possible to recognize that "e" in these situations
> could never be confused with other possible tags known as "e".
>
> Same can be said for the "i" construct for complex numbers.
>
> But, this interpretation of mine is quite naive to the more serious
> language aspects.

Well, plus-i-times is a monad, we cannot do anything about that :/

> At any rate, the backslash (\) as a substitute for "e" could seriously
> confuse folks and might find better uses elsewhere.

Yes I agree.  I think we should use "e" to represent
times-ten-to-the-power-symbol.

>
> On Mon, Feb 9, 2026 at 1:49 PM Jose E. Marchesi <jemarch@gnu.org> wrote:
>>
>>
>> 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.