Support inference rules

[connorjayr]

Is your feature request related to a problem? Please describe.
Willow does not currently support the use of logical inference rules in truth trees.

Describe the solution you'd like
Users should be able to apply inference rules to statements in the truth tree. Any statements that are the result of an inference should only be considered fully decomposed if its typical decomposition occurs in all child branches. See the inference rules of KE Calculus for examples.

Describe alternatives you've considered
We could start with implementing simpler rules, such as the ones in KE Calculus.

Additional context

• https://homepages.hass.rpi.edu/heuveb/Teaching/Logic/CompLogic/Web/Presentations/TF-Trees.pdf