About The Logic App 2.1
The Formula List tab
- Use the toolbar at the top of the screen to add and delete formulas.
- The toolbar also lets you save the formulas to disk, change the symbols, and copy the formulas to the Derivation tab.
The Semantics tab
- Use the toolbar at the top of the screen to generate truth tables, and to test consistency and validity.
The Derivations tab
- The assumptions of the derivation are coloured green. Lines that are derivable from previous lines are coloured blue.
- Use the Rules selection on the toolbar to choose the derivation system.
- The Logic App includes these derivation systems:
- The system SD from The Logic Book.
- The propositional system F from Language, Proof, and Logic.
- The sentential derivation system from R.L. Simpson's Essentials of Symbolic Logic.
- Generic derivation rules can also be selected individually. Click here for a list of available rules.
The Truth Tree tab
- Double-tap a formula to decompose it. Decomposed formulas are coloured green.
- Formulas at the end of closed branches are coloured red.
- Touch and hold a formula to move it and the branches below it.
The Library tab
- Use the toolbar to load fomula lists and derivations you have saved.