Enter one or more sentences of truth-functional logic in the space below. Separate multiple sentences with commas.
Use the following symbols for the logical operators.
~ | for negation |
& | for conjunction |
v | for disjunction |
-> | for the conditional |
<-> | for the biconditional |
# | for absurdity |
| | for NAND (the Sheffer Stroke) |
! | for NOR (Wittgenstein's Sheffer Stroke) |
These are some examples of well-formed inputs that the program will accept.
~P |
(P & Q) |
(P & (~Q -> S)) |
(# -> (Q v ~P)) |
(P|Q) <-> ~(P & Q) |
(P <-> (Q v S)), P, (~Q -> S) |
A sentence of TFL is a tautology if and only if it is true on every truth-value assignment. (I.e., there is a “T” on every line below the main logical operator.)
An argument, P1, P2, ... ⊢ C, is valid when ((P1 & P2) & ...) → C is a tautology.
Two sentences, A and B, are equivalent when (A ↔ B) is a tautology.
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