PSOA Prova enriches PSOA RuleML with parts of Reaction RuleML. It is implemented by combining PSOATransRun and Prova, a Prolog-based language and engine which supports object orientation, reactive programming as well as several other programming paradigms. A modified Prova engine targeted by PSOA RuleML's PSOATransRun translators is introduced and then extended to top-level assert and retract by allowing KB consult and unconsult at runtime. PSOA is further extended to pure production rules, a conclusion-asserting subset of Production RuleML, hence Reaction RuleML. This is exemplified for a PSOA Prova knowledge base about the British ``Succession to the Crown Act 2013''. These extensions yield a PSOA Prova language and engine available on GitHub. Three formalization approaches for succession are demonstrated.