Re: origin of := and =:

In article <1128009784.621228.311890@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Artur <artur_steiner@xxxxxxxxx> wrote:
>I've seen some authors use the symbol := to define functions quicly and
>precisely . So, "Let f(x) := x^2, x in R" means "Let f be the function
>defined by f(x) = x^2, x in R". If instead of := you just put = , then,
>to be precise, the staement is wrong, because f(x) is not the function
>itself (that old confusion of a function and its values).

No, ->you're<- confusing the function with its values. The function is
f. "f(x)" is the value of the function at the point x. Writing
"f(x)=x^2" is perfectly correct, as it gives you the way in which the
value of f at the point x is defined.

--
======================================================================
"It's not denial. I'm just very selective about
what I accept as reality."
--- Calvin ("Calvin and Hobbes")
======================================================================

Arturo Magidin
magidin@xxxxxxxxxxxxxxxxx

.

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