RE: IBM 1620 invalid character symbol

From: Ian Clifton via Unicode <>
Date: Tue, 26 Sep 2017 16:23:56 +0000

William Overington wrote:

> A digit with a bar over the top is used to express the common logarithm of a number that is both greater
> than zero and also less than one.


Gosh, I’d forgotten that usage, although I now remember being taught it at school.

Another use of over bar for negative numbers is in crystallography—I believe the motivation is that it’s useful
to have a very compact notation for (often space separated triples of) small integers of either sign.

Ian Clifton
Received on Tue Sep 26 2017 - 11:24:17 CDT

This archive was generated by hypermail 2.2.0 : Tue Sep 26 2017 - 11:24:17 CDT