In this minimalistic puzzle game, you're given a set of premises and a conclusion, and your task is to use the fundamental rules of logic to formally prove, step by step, that the conclusion follows.

Tutorials introduce you to the world of proofs and the game mechanics. The early problems are simple, but the difficulty gradually increases until eventually you might not even know where to begin. Still, every problem has a solution, and if you think deeply enough, you'll never need to guess!

  • Simple controls. No timers. No distractions. Just logic.
  • 111 problems to solve, including classic theorems like De Morgan's Laws and the Law of the Excluded Middle
  • Sandbox mode: enter any claim (with proposition symbols A–H) and see if you can prove it!

NOTE: To run the MacOS version, double clicking may not work. Instead, try right-clicking the app and choosing 'Open' in the menu and then again 'Open' in the confirmation dialog.

StatusReleased
PlatformsHTML5, Windows, macOS, Linux, Android
Rating
Rated 5.0 out of 5 stars
(3 total ratings)
Authornonpop
GenrePuzzle, Educational
Made withGodot
TagsAbstract, Indie, logic, Math, Minimalist, Mouse only, Touch-Friendly
Average sessionA few minutes
LanguagesEnglish
InputsMouse, Touchscreen, Smartphone

Purchase

Buy Now$5.00 USD or more

In order to download this game you must purchase it at or above the minimum price of $5 USD. You will get access to the following files:

deductum-windows.zip 38 MB
deductum-linux.zip 31 MB
deductum-macos.zip 62 MB
deductum-android.apk 31 MB

Development log

Comments

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The full version does not include:
<-> (implies and vise versa)
-/> (does not imply)
<-
</-
Extra proofs:
A, A -/> B | not B
A, A <-> B | B
not A, A <-> B | not B

Thanks for the comment! I indeed dropped equivalence (<->) because I thought it would clutter the UI without bringing interesting new mechanics. Maybe I'll include it in a future version, though. I'll also add your proof suggestions to a list of possible future additions!

More proofs: A <-> B | A -> B, B -> A
A -> B | A -/> not B
A -/> B | A -> not B
not not A | B
A -> B | B -> A
A <-> B | A -> B, B -> A
A and B | A <-> B
not A and not B | A <-> B
A <-> B | A and B or not A and not B
not A <-> B | not A and B or A and not B
Level ideas:
1.
Premise: A -/> B
Prove: A -> not B
2.
Premises: A -> B, B -/> C
Prove: A -> not C
3.
Premise: A -/> not B
Prove: A -> B
4.
Premise: A <-> B
Prove: A -> B and B -> A
5.
Premise: A and B
Prove: not(A -/> B)
6.
Prove: (not A) -/> A
7.
Prove: (A and A-/> B) -> (A <-> B)