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A priori (law), based on deduction or hypothesis

A priori (languages), a type of constructed language

A priori (statistics), a knowledge of the actual population

A priori (math modeling)

A priori and a posteriori (philosophy), used to distinguish two types of propositional knowledge

A priori (mathematics) - in mathematical literature, one often says proposition A "does not a priori imply" proposition B if any such implication would require some nontrivial reasoning. In particular, the question of whether proposition A implies proposition B a priori is independent of whether proposition A implies proposition B in fact.