indirect proof

American  

noun

1. an argument for a proposition that shows its negation to be incompatible with a previously accepted or established premise.

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indirect proof British  

noun

1. logic maths proof of a conclusion by showing its negation to be self-contradictory; reductio ad absurdum Compare direct

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Example Sentences

See Examples For:

indirect proof

They have never been seen directly, though an indirect proof of their existence, based on studying a pair of collapsed stars, was rewarded with the 1993 Nobel prize in physics.

From Economist ● Mar. 20, 2014

I was about to begin going over the steps of indirect proof when I heard Danny say, “You’re always sleeping! What a sleepyhead you are!” and I opened my eyes.

From "The Chosen" by Chaim Potok

And we have, as has been pointed out, interesting indirect proof as to what manner of life He lived on those workaday levels that we all know so much about.

From One Day at a Time and Other Talks on Life and Religion by Arch. Alexander

The very ferocity with which the pretensions of the Court were assailed in certain quarters was indirect proof of its power, but there was also direct testimony of a high order.

From John Marshall and the Constitution; a chronicle of the Supreme court by Edward Samuel Corwin

An indirect proof of this is given by the fact, that legal practice was labouring to discover means of protection for possession based on temporary agreement.

From Villainage in England Essays in English Mediaeval History by Paul Vinogradoff