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Short guides to propositional logic and to each tool, from the first idea to the details. Start with the basics, or open the guide for the tool you are using.
- Start herePropositional logic basicsSentences, connectives, and four ideas that every tool builds on: validity, consistency, equivalence and tautology. Start here if logic is new to you.
- Truth tablesSettle questions about formulas and arguments by listing every combination of true and false.
- TableauxTest a claim by trying to build a counterexample, breaking formulas apart branch by branch.
- ProofsDerive a conclusion from premises with a Fitch proof, one justified line at a time.
- Syntax treesSee how a formula is built from smaller formulas, and how to find its main connective.
- Normal formsRewrite a formula as an AND of ORs or an OR of ANDs, one equivalence at a time.