Adjunction is a basic rule of inference in logic logic by which two formulas, or propositions, can be joined together to form a conjunction. Adjunction states that if formula "P" is true, and formula "Q" is true, then the formula "P ∧ Q" is true. Adjunction is also known as the conjunction introduction rule of inference, or ∧I, as it introduces a new conjunction into an argument or proof.
Adjunction may be formally presented as follows:
α, β 
α ∧ β