Hi, thanks a lot for this flake8 library, It's been helping us a lot with keeping a nice code quality 1

I think we've spotted a small issue when it comes to replacing not < with >= rules using sets.

Desired change

• Rule(s): SIM204, SIM205, SIM206, SIM207
• Adjustment:

Using sets, saying not (a < b) is not equivalent to a >= b:

• not (a < b): there is no element of a that is in b
• a >= b: all elements of b are in a

I am unsure what the adjustment should be, maybe omit these rules when comparing sets ?

Explanation

On sets, (not (a < b)) != (b >= a)

Example

This is an example where the mentioned rule(s) would currently be suboptimal:

a = {4, 5}
b = {1, 2, 3}

# this raises: SIM204 Use 'a >= b' instead of 'not (a < b)'
assert not (a < b)   # no elements of a are in b; would pass 

# when making the suggesting change:
assert a >= b  # all elements of b are in a -> AssertionError