Bug introduced in 9.0 or earlier and fixed in 10.4
The following code using PiecewiseExpand
and Mod
gives the wrong answer
PiecewiseExpand[Mod[n, m], m > 0, Integers]
0
tested in Mathematica v 10.2.0 Windows 7 64 and partially discussed on early version of this question.
Wolfram Technical Support case identification : [CASE:3442254]
Can anybody reproduce this problem in other systems?
$Assumptions = m > 0 && Element[{n, m}, Integers]; PiecewiseExpand[Mod[n, m]]
returnsMod[n, m]
$\endgroup$ – Bob Hanlon Oct 9 '15 at 16:39