About this app
This free app allows users of propositional logic to perform operations with the same ease as that offered by a mathematical calculator. It facilitates learners of logic by providing considerable feedback. To be precise, using this app, one can determine whether: (1) input is well-formed and, if not, why not, (2) sentences are tautologies, contradictions or contingent, (3) sets of sentences are consistent or inconsistent and (4) arguments are valid or invalid. It also produces truth tables which can be copied into other applications. As of this version, the calculator is restricted to semantic operations.
Latest release
What’s New
* Bug Fixes * More Examples of How to Use the Calculator
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 22, 2026 · 7:16 PM Free