Function discharge_obligation 

pub fn discharge_obligation(norm: &mut NQuin, facts: &[NQuin]) -> DeonticStatus

Discharge an obligation by fulfilment: if the bearer brought the obligation’s content about, the duty is Discharged and consumed (linear::consume_quin — a duty paid is spent once, not reusable). Returns the status; mutates norm to mark consumption on discharge. A non-obligation, or an unfulfilled one, is left unconsumed.