given that m,n are optional inputs to CRT(a,b,m,n), given a,b mod m,n should work

[was]

I think this should work:

sage: CRT(Mod(3,19), Mod(5, 13))
...
ValueError: arguments a and b must be coprime

This fix is to check the gcd precondition more carefully.

[saiharsh]

I have tried

sage: CRT(Mod(3,19), Mod(5, 13))

The error is because of the return type of Mod is sage.rings.finite_rings.integer_mod.IntegerMod_int, not integer which is desire.

if you try this

sage: CRT(int(Mod(3,19)), int(Mod(5, 13)))

it's working, is my suggestion right? or am I missing something.

I used Sage version 8.1, which was released on 2017-12-07.

Thanks,
Harsh