1. Abbreviation of the Latin phrase "quod erat demonstrandum;
literally, "that which was to be demonstrated". Commonly used at the end of mathematical proofs to signify the
proof is complete.
2. Modern usage expands it to include the conclusion of any proof and is often used in attempts at
ironic humor.
3. Quantum electrodynamics.
1. If A=B and B=C then A=C. Q.E.D.
2. Beckham and Ronaldo move to MLS. MLS attracts more fans and makes more
money. More
money attracts more quality players. More quality players make
USA competitive. USA wins World Cup. Q.E.D.