arithmetic-propositional-formula

This simple script can be used to check whether a given propositional formula is a tautology. It uses arithmetic method and works recursively.

Usage

1. Change the test formula variable to your own formula.
2. Set test variables
3. Run the script: python propositional-formula.py

Notes

The formula should be a string or a tuple/list of strings.

The function works recursively and it only works with 1 (variable), 2 (NOT) or 3 arguments (binary operators).

For example (("p", "OR", "q"), "OR", "r") is supported (it contains 3 arguments, altough one is a nested tuple), but ("p", "OR", "q", "OR", "r") is not (because it contains 5 arguments).

The operators should be infix, but that can be easily changed by reordering variables on line 33:

left, op, right = formula

You can check examples.py for a couple of examples how the test formula should look like.