Why is the "<" symbol named the "less-than sign"?

Wed Sep 16 07:36:11 CDT 2020

Am Mittwoch, 16. September 2020 um 12:43 schrieb Roger L Costello via Unicode:

RLCvU> Hi Folks,

RLCvU> Just curious ...

RLCvU> I realize that mathematicians use the "<" symbol to denote the
RLCvU> less-than relation. Who decided that that symbol would denote the less-than relation?

According to the German Wikipedia:
 https://de.wikipedia.org/wiki/Vergleichszeichen#Geschichte
the symbols were devised 1631 by Thomas Harriot in his book "Artis
 analyticae praxis".
(Until now, the English wikipedia lacks this information.)

RLCvU> The "<" symbol looks like a "v" turned sideways. How does a
RLCvU> sideways "v" symbol connote less-than?

It is not derived from a "v", as this picture shows (scan from the
 aforementioned book):
https://commons.wikimedia.org/wiki/File:Artis_analyticae_praxis_1631_%E2%80%93_Comparationis_signa_in_sequentibus_usurpanda.png

RLCvU> The "<" symbol is used in other places where it has nothing to
RLCvU> do with less-than. For example, it is used in HTML and XML such as this: <body>

RLCvU> I suspect there are many places where it is used and has nothing to do with less-than.

RLCvU> So why is the "<" symbol named the "less-than sign"?

Presumably, as the other uses are recent and motivated by the fact
that some new features had to be implemented by the then available
ASCII characters, which then already had their name.

- Karl

RLCvU> /Roger