Hypersequent

Hypersequent is a concept from mathematical logic, specifically in proof theory. It extends the notion of sequent calculus, which is a formal system used for expressing proofs in a structured way. In traditional sequent calculus, a sequent is typically represented in the form \( \Gamma \vdash \phi \), where \( \Gamma \) is a set (or multiset) of formulas (premises) and \( \phi \) is a single formula (the conclusion).