A relation between a set of statements (finite, infinite, or empty), $\text{Σ}$ (the premisses), and a statement, $\phi$ (the conclusion), which holds when $\phi$ follows logically from the members of $\text{Σ}$. In multiple conclusion logic, the single conclusion is replaced by a set of conclusions, $\text{Π}$, interpreted, intuitively, as a disjunction. A consequence relation may be either a syntactic consequence relation, $⊢$, or a semantic consequence relation, $\models$.