The game in this repository is meant to introduce the player to the area of Combinatory logic through a series of short logic puzzles. The puzzles used here are mainly inspired by the ones in Raymond Smullyan's excellent book "To Mock a Mockingbird".
This game is intended to be played using the LEAN theorem prover, although the puzzles can be solved independently as well (it is a lot more fun to use LEAN!). If you do not have LEAN installed, you can play the online version of this game here.
If you are new to LEAN, you can find a list of resources for getting started on the LEAN prover community website.
The main tactics you will need for this game are:
rw- used to rewrite equalitiesintro- used to pick an arbitrary bird in the forestexistsi- used to specify a particular bird required to complete a goal
The objective of the game is to fill in the sorrys with LEAN proofs of the puzzles. If you are stuck, solutions are available in this file.
A description of all the birds and their calls can be found in the birdcall.md file.