Geometric theory
= Geometric theory
{title2=$\mathbb T=\{\phi\vdash_{\vec x}\psi\}$}
A set of sequents between <geometric formulas> over a many-sorted signature. Its <geometric syntactic category> and <geometric syntactic topology> yield its <classifying topos>. A model satisfies a sequent when the interpreted antecedent <subobject> is contained in the consequent in the indicated context.