論理学ドリル -命題論理・自然演繹・真理値トレーニング-

Logic Drill takes you from your first logical symbols through natural deduction and predicate logic, one step at a time. The app has 9 chapters of text and 10 drill units. Each unit works through a set of stages — read, tell apart, choose, connect, build — skipping any stage that doesn't fit the content (translation and fallacy units, for example, don't need all five). ■ What you'll learn • Logical connectives and truth tables • Tautologies, contradictions, and the validity of an argument • Natural deduction (∧, →, ∨, negation, reductio ad absurdum) • Predicate logic (∀, ∃) • Translating everyday sentences into logical formulas • Formal and informal fallacies • Sequent calculus (Γ ⊢ Δ) ■ Designed to be easy to work through • Learn what the symbols mean starting from everyday words like "and," "or," and "not" • A built-in truth table calculator checks any formula you enter, instantly • Translation answers are checked for logical equivalence, not just matching text • For invalid arguments, you can see a counterexample where the premises hold but the conclusion doesn't • Progress is saved on your device — no account needed The app shows a banner ad at the bottom of the screen. A one-time in-app purchase removes ads. There's no reward-ad tier, no subscription, and no AI explanation feature.