absolute
actual
admitting no question
confirmable
demonstrable
demonstratable
factual
historical
inappealable
incontestable
incontrovertible
indisputable
indubitable
irrefragable
irrefutable
provable
real
self-evident
testable
unanswerable
unanswered
unconfutable
unconfuted
uncontradicted
uncontroverted
undeniable
undenied
unimpeachable
unquestionable
unrefuted
verifiable