Answer: proven

AnswerCrossword Clue
PROVENMathematically validated
provento establish the truth, validity, or worth of
provenPROVE, to establish as certain or true
provento turn out
provento be found to be
PROVENMarked with a "QED"
PROVENQED
PROVENTried and true
PROVENEstablished as fact
PROVENShown to be a fact
PROVENInnocent until -- guilty
PROVENSubstantiated
PROVENLike Fermat's last theorem, eventually
PROVENLike an ironclad case
PROVENDocumented
PROVENTried
PROVENVerified
PROVENMade clear.
PROVENTested.
PROVENDemonstrated.
PROVENEstablished
PROVENShown as true
PROVENEstablished via evidence
PROVENNo longer in doubt
PROVENDemonstrated