necessarily or demonstrably true; "demonstrable truths"
capable of being demonstrated or proved; "obvious lies"; "a demonstrable lack of concern for the general welfare"; "practical truth provable to all men"- Walter Bagehot
unmistakably (`plain' is often used informally for `plainly'); "the answer is obviously wrong"; "she was in bed and evidently in great pain"; "he was manifestly too important to leave off the guest list"; "it is all patently nonsense"; "she has apparently been living here for some time"; "I thought he owned the property, but apparently not"; "You are plainly wrong"; "he is plain stubborn"