Avoid crashing Mathematica while using Reduce?

Ideas
,
1

v. 11.1.0.0

Reduce[Arg[a] + Arg[b] == Arg[a*b], {a, b}]

Edited to add steps to reproduce: Start Mathematica from scratch, enter that input, and within a minute Mathematica beeps, and when I ask it why the beep (under the Help menu), it says the Kernel has quit. That’s what I mean by “crash”. For me it’s normally reproducible, though on one trial it ran for a few minutes without beeping (until I gave up and cancelled.)

2

From your input, Mathematica assumes that the variables are complex. Try

Reduce[Arg[a] + Arg[b] == Arg[a*b], {a, b}, Reals]
1 Like
3

Thank you, but that would be a different query, as I was asking it about complex variables.

4

I have not replicated the crash in our current development builds but I did see some assertion failures, possibly benign, in a debugging version. Sent the example to the relevant developers so that part at least should get investigated.

1 Like
5

Thank you.