Re: [Chicken-hackers] CR: expt should signal error on domain error

[John Cowan]

Felix scripsit:

> Is this intuition, or are you simply being used to it? I learned in
> School that division by zero is invalid.

I'm sure you also learned such rules as:

        0.10000000000000001 /= 0.10000000000000000
        x < x + 1
        x - x = 0
        x + y = y + x
        (x + y) + z = x + (y + z)
        Exactly one of x < y, x = y, or x > y is true.

But none of these are (reliably) true of flonums.

> Nobody told me about nonsense like positive or negative zero, or
> numbers that aren't. That is unintuitive.  Unfortunately we take
> conventions born out of technical peculiarities or peformance hacks
> for granted.

Flonums have a perfectly coherent mathematical theory; it just isn't the
one associated with ordinary numbers, but a sort of specialized algebra
of intervals.

> This deeply disappoints me. You all are a bunch of robots.

Not at all!

        A little Learning is a dang'rous Thing;
        Drink deep, or taste not the Pierian Spring:
        There shallow Draughts intoxicate the Brain,
        And drinking largely sobers us again.
                --Alexander Pope, "An Essay upon Criticism" (1711)

The Pierian spring in Macedonia was sacred to the Muses; "largely" here
means "in large quantity".

-- 
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