quod erat demonstrandum

[ kwawd e-raht dey-mawn-strahn-doom; English kwod er-uht dem-uhn-stran-duhm ]

Latin.

1. which was to be shown or demonstrated.

quod erat demonstrandum

/ ˈkwɒd ˈɛræt ˌdɛmənˈstrændʊm /

(no translation)

1. (at the conclusion of a proof, esp of a theorem in Euclidean geometry) which was to be proved QED

quod erat demonstrandum

1. A phrase used to signal that a proof has just been completed. From Latin , meaning “that which was to be demonstrated.”

Example Sentences

He might usefully have concluded his column with the letters we had to put next to solved mathematical equations: QED — quod erat demonstrandum — just to prove his point.

From Washington Post

At one point, he quotes approvingly a passage from Mein Kampf on how “Marxism itself systematically plans to hand the world over to the Jews”, and then insists that “Well, you can’t argue with logic of that calibre. No: quod erat demonstrandum. Next question, please.”

From Slate

QED: quod erat demonstrandum, Latin for “which was to be demonstrated or proved.”

From Literature

“Burning Bush” joins the ranks of other recent films from the former Eastern Bloc — like “Ida” from Poland, “Quod Erat Demonstrandum” from Romania, “Barbara” from Germany — that try to grasp, with the benefit of hindsight but without too much ex post facto gloating, the logic of Communist dictatorship.

From New York Times

Queen's Counsel; Queen's College. q.d., quasi dicat=As if he should say. q.e., quod est=Which is. q.e.d., quod erat demonstrandum=Which was to be demonstrated. q.e.f., quod erat faciendum=Which was to be done. q.e.i, quod erat inveniendum=Which was to be found out. q.l., quantum libet=As much as you please.

From Project Gutenberg