smichr/sympy — comment on commit 96ec4488ea2e8b6de4ecfd9087a12d871d951550
File: sympy/polys/galoistools.py line 2237
By hector1618:

`` x cong -6 mod 8 `` is equivalent to `` x cong 2 mod 8 `` but it is **not** equivalent to ``x cong 1 mod 4``.

At the present state -

```python
In [17]: solve_congruence(*zip((1, 1, 2),(3, 2, 4)))
Out[17]: (1, 6)
```
I modified **reduced** a little,

```python
def reduced(a, b):
"""Return a and b after removing gcd and making a positive,
e.g. -6, 8 -> 2, 8"""
#g = igcd(a, b)
#b //= g
return a % b, b
```
And now it works as -

```python
In [4]: solve_congruence(*zip((1, 1, 2),(3, 2, 4))) is None
Out[4]: True
```
So, **normalize** would be more appropriate name then **reduce** for this function.