Bug in "is" ?
Wacek Kusnierczyk wrote:
Peter Dalgaard wrote:
Stefan Evert wrote:
... am I the only one who thinks that the integer 7 is something
entirely different from the real number 7.0? (The latter most likely
being an equivalence class of sequences of rational numbers, but that
depends on your axiomatisation of real numbers.) Integers can be
embedded in the set of real numbers, but that doesn't make them the
same mathematically.
Several people have tried to make that point (or something very
similar), but it doesn't seem to take.
It might get clearer if taken one step up: is.double(-1+0i) is not true
either, even though the real line is cleanly embedded in complex space,
-1+0i is not the same as -1. For instance, you can take the square root
of the former but not the latter.
you see, there seems to be a confusion of *numbers* and their *representations*. but of course the integer 7 is *the same* number as the real number 1.0,
oops, a typo; the integer 7 is the same number as the real number *7.0*. every integer is real, and the set of real numbers does not contain both the integer 7 and the real 7.0 as two distinct numbers. vQ