Maximal consistent set of first-order sentences (source code)

= Maximal consistent set of first-order sentences

= Maximal consistent
{synonym}

A consistent set of first-order sentences is maximal when adding any new sentence makes it inconsistent. It is then deductively closed and decides every sentence by containing exactly one of it and its <negation>. Conversely a consistent deductively closed set that decides every sentence is maximal. Merely listing a finite axiom set for a complete theory does not make that raw list maximal: maximality applies to the deductive closure.