Q.E.D.

Q.E.D.phrase/ˌkjuːiːˈdiː/

• 1

  Used to indicate that an argument or proposition is proved by the existence of some fact or scenario.

  • That this part of the world has actually been peopled (Q. E. D.) to support which, we have living proofs in the numerous tribes of Indians that inhabit it.
  • PROP[OSITION] VI. One substance cannot be produced by another substance. ¶ Demonst[ration]. In the preceding proposition we have seen that there cannot in the nature of things be two Substances of the same attribute, or that they have anything in common (by Prop. II.); and so (by Prop. III.) one cannot be the cause of, or be produced by, another: q. e. d.

Q.E.D.noun/ˌkjuːiːˈdiː/

• 1

  A certain fact or scenario that proves an argument or proposition; a justification.

  • We all go in for the dolce here except you, and you're such a patent machine for turning out Q.E.D.s by the dozen, that you can no more help working than the bedmaker can help taking my tea and saying the cat did it,[…]
  • The same thing, I believe, that was lacking in Let Freedom Ring—lack of dramatic integration, lack of dramatic intensity, lack of all those elements, call them what you will, which make a play a play and not a tract, and certainly not a Q.E.D. thesis.

這個拼法也被記錄為下列字的變化形：

• quod erat demonstrandum