Interactive tools for a logic course. Each one takes a formula and works through a method step by step, checking every move rather than just handing over an answer.
They all read the same syntax: ¬ ∧ ∨ ⊃ ≡, with ⊃ for implication and ≡ for the biconditional. Variables are letters.
If those characters are awkward to type, ~ & | -> <-> work
just as well, as do !, /\, \/, =>
and the arrows → and ↔. Each page also has a row of
buttons that insert the symbols for you.