The law of the excluded middle is a law in most logical systems which states that for any proposition, either that proposition or its negation must be true.
The law of the excluded middle may be formally expressed as:
P ∨ ¬P
This is related to the law of the excluded middle, which states that either a proposition or its negation must be true. The law of the excluded middle and the law of noncontradiction may be formally represented as:
(P ∨ ¬P) ∧ ¬(P & ¬P)
Alternatively, in systems which use a symbol for an exclusive disjunction (⊕ or XOR), the laws of the excluded middle and noncontradiction may together be formulated as:
P ⊕ ¬P