[TUHS] Slashes

John Cowan cowan at mercury.ccil.org
Sun Jul 10 01:59:51 AEST 2016

Doug McIlroy scripsit:

> This is sheer hypothesis, but I have always thought that \ got
> onto printer chains and type balls as a crude drawing aid. Ditto
> for |. Once the characters became available people began to find
> uses for them.

<http://www.bobbemer.com/BACSLASH.HTM> tells us that \ was introduced
into ASCII by Bob Bemer in order to make \/ for 'or' and /\ for 'and'
available, primarily for the use of Algol 60.  It had not been available
in any manufacturer's character set before ASCII-63, as far as is known.
Unfortunately, none of the five existing Algol 60 implementations actually
support these sequences.

| was commonplace, however, as it has at least 15 mathematical uses:
see <https://en.wikipedia.org/wiki/Vertical_bar#Mathematics>.
As far as I know, it has always been used as 'or' on computers.

John Cowan          http://www.ccil.org/~cowan        cowan at ccil.org
If I have seen farther than others, it is because I am surrounded by dwarves.
        --Murray Gell-Mann

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