Rule of Conjunction/Proof Rule/Tableau Form

Proof Rule
Let $\phi$ and $\psi$ be two propositional formulas in a tableau proof.

The Rule of Conjunction is invoked for $\phi$ and $\psi$ in the following manner:

Also denoted as
Sources which refer to this rule as the rule of adjunction may as a consequence give the abbreviation $\operatorname {Adj}$.