Rule of Commutation/Disjunction

Theorem

Disjunction is commutative:

Formulation 1

$p \lor q \dashv \vdash q \lor p$

Formulation 2

$\vdash \paren {p \lor q} \iff \paren {q \lor p}$

Its abbreviation in a tableau proof is $\text{Comm}$.

Also see

• Rule of Association
• Principle of Commutation