[Haskell-cafe] Origins of '$'
dpiponi at gmail.com
Mon Dec 8 13:36:08 EST 2008
On Sun, Dec 7, 2008 at 2:05 AM, Hans Aberg <haberg at math.su.se> wrote:
> As for the operator itself, it appears in Alonzo Church, "The Calculi of
> Lambda-Conversion", where it is written as exponentiation, like x^f
That's reminiscent of the notation in Lambek and Scott where (roughly
speaking) the function converting an element of an object A^B to an
arrow B->A (something Haskellers don't normally have to think about)
is written as a superscript integral sign. Presumably this comes from
the same source. Both $ and the integral sign are forms of the letter
's'. Don't know why 's' would be chosen though.
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