  Factivity of justifications is not required in basic Justification Logic  systems, which makes them capable of representing both partial and factive justifications. The Factivity Axiom appeared in the Logic of Proofs  \(\mathsf{LP}\), Section 1.2, as  a principal feature of mathematical proofs. Indeed, in this setting  Factivity is clearly valid: if there is a mathematical proof  \(t\) of \(F\), then \(F\) must be true.