QED is commonly understood to mean "the theorem is proved," and it is used in rigorous mathematical proofs that leave no doubt of their meaning. From wikipedia

QED is commonly understood to mean "the theorem is proved," and it is used in rigorous mathematical proofs that leave no doubt of their meaning. From wikipedia (http://en.wikipedia.org/wiki/Q.E.D. http://en.wikipedia.org/wiki/Q.E.D.): The phrase is traditionally placed in its abbreviated form at the end of a mathematical proof or philosophical argument when that which was specified in the enunciation, and in the setting-out, has been exactly restated as the conclusion of the demonstration. I agree with the parent comment that this rhetorical flourish is misleading, and I agree it gives the non-scientific set a hook to riff on.