[HM] Z and Q [was: the importance of notation]

Walter Felscher (walter.felscher@uni-tuebingen.de)
Thu, 13 May 1999 22:40:23 +0200 (MEST)

The desire to denote particular domains of computation by
particular letters does not occur with the authors of classical
textbooks such as Weber and Fricke. The firsts textbooks I have
found it in are

Helmut Hasse: H"ohere Algebra I and II , Berlin 1926

who wrote <capital gamma> for the integers,
<capital rho> for the rationals

and kept to this notation also in his later books on number
theory,

Otto Haupt: Einf"uhrung in die Algebra I and II , Leipzig 1929

who wrote <italic> G <upper index (0)> for the integers,
<capital rho , upper index (0)> for the rationals

van der Waerden: Moderne Algebra I , Berlin 1930

who wrote C for the integers,
<capital gamma> for the rationals.

In editions during the sixties, van der Waerden changed to Z
and Q .

So there seems to be no earlier occurrence of Z and Q than that
in Bourbaki's Alg\ebre, Chap. 1

I wonder about the suggestion made by Mr.Conway that Q may have a
connection with the German word Querschnitt, i.e. cross section.

W.F.