Summary

Prior to this change, we treated all unary operations applied to a dynamic value as producing the same dynamic type. This is appropriate for +, -, and ~, whose dunder implementations may return arbitrary values, but not for not: Python always produces a bool after evaluating its operand's truthiness.

from typing import Any, reveal_type

def check(value: Any) -> None:
    result = reveal_type(not value)  # bool
    result.nonexistent()  # error: `bool` has no attribute `nonexistent`

We now allow not on dynamic operands to use the existing truthiness-inference path, while retaining dynamic propagation for the other unary operators. This restores downstream checking of the resulting boolean value.

Closes astral-sh/ty#3572.