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This is a puzzle game like a mathematical book, based on logic and deduction. In this game, you don't need to beat the level, but need to prove it is beatable. Your goal is not to win, but to prove you can win.
Price history tracked since Jul 7, 2026 · vs all tracked offers.
Based solely on tracked price history — not purchase advice.
Tracked since Jul 7, 2026.
Steam Social Deduction Fest ends
Try this game before buying.
This is a puzzle game based on logic and deduction. In this game, you can learn and understand a brand new deduction system, and then take the axioms and rules of deduction as tools, to prove the propositions by entering the code.
Features:
Understand the axioms and rules of deduction (just like when you are reading a mathematical book)
Enter the code and prove the proposition (just like when you are solving a math problem)
"Q.E.D.", "Eureka!", and get into the next loop
Elements which might be frustrating:
No good artwork. (That's less important than the other three)
Amounts of text to read, and it requires a little comprehension of math. (Playing this game is virtually like reading a math book)
The only way to create a new proof step is entering the right code, which is not the core of the game essentially. (It's due to my limited programming ability)
No custom-corollary function. Only the axioms and rules of deduction are available. (Welcome to the CLASSIC deduction system)
If all of them are okay for you, then this game may be suitable for you.
FAQs:
Q: Which players are the game mainly for?
A: If you have some experience of reading math books and you are interested in logic, this game may be the one you like.
Q: Is it a hard game?
A: At the first, the difficulty of this game are mainly about the understanding the rules, and it's easy to work out the puzzle. But the problem will become very hard if you keep playing. Anyway, reading and comprehending themselves will form a part of difficulty.
Q: Are you inspired by something when designing this game?
A: This game is inspired by mathematical logic, mainly about natural deduction of statement calculus and first-order predicate calculus.
Q: How long does it take to beat the game?
A: About 20~40 hours.
Q: Is there any difference between this game and a mathematical exercise book?
A: Nothing. And I just let it be. If some players mind that, it's fine by me to use "the executable file" or "the exercise book" while talking with them, instead of "this game".
