The Playable Hands Tool allows us to do a "reverse equity" calculation. Given an opposing range of hands,
we can compute what hands have a given minimum amount of equity.
For instance, if our opponent has any pair or any ace, and we need 45% equity to call, we discover that we can
play a pair of threes or higher, an ace with a nine or higher, or an ace-eight suited:
Here is another example. If the board has AJ5 rainbow, our opponent has an ace (or aces), and
we need 40% equity, we can play aces, jacks, fives, an ace with an 8 or higher, ace-five, or jack-five: