Welcome
A logic tutor that generates problems, checks your answers, and tracks your progress.
Pick Exercise Sets to begin. Earn 100 points to complete a set. Right answers add points; wrong answers cost points (more at higher scoring levels). It's "no-fault": only completions are recorded, and you keep the highest level you reach.
Areas of logic in this book
▶ Show the topics and their exercise sets
- Categorical logic — reasoning with "all," "no," and "some" about classes of things. Sets A, B
- Propositional logic — reasoning with whole statements joined by "and," "or," "if-then," and "not." Sets C–G
- Quantificational (predicate) logic — reasoning with properties, relations, and identity using quantifiers. Sets H, I
- Modal logic — reasoning about what's necessary or possible. Sets J, K
- Deontic logic — reasoning about what's obligatory, permitted, or forbidden. Sets L, M
- Belief logic — reasoning about what people believe, and what rational belief requires. Sets N, O
- Probability — working out odds, probabilities, and expected value. Set P
- Definitions — spotting what's wrong with a proposed definition. Set Q
- Fallacies — naming the common mistakes that make bad arguments look convincing. Set R
Master a proof set — G, I, or K — at level 9 to unlock its ungraded Proof Builder, a free-form practice workspace. Instructor edition: all proof builders and the Non-Classical Workbench (free · intuitionistic · medieval term logic — validity checker & proof builder) are open with no level-9 unlocks.