The first letter of the Hebrew alphabet. It was first used
in mathematics by Georg Cantor to denote
the various orders, or sizes, of infinity:
aleph-null, aleph-one, etc. An earlier (and still used) symbol for infinity,
looking like an "8" on its side, was introduced in 1655 by John Wallis
in his Arithmetica infinitorum but didn't appear in print until the
Ars conjectandi by Jakob Bernoulli,
published posthumously in 1713 by his nephew Nikolaus Bernoulli.