What is the origin of the phrase "as desired" in mathematics?

Question

This is a sort of strange question that popped into my head when I was reading a paper. In writing mathematics, many authors use the phrase "as desired" to conclude a proof, usually written to indicate that one has reached the result originally stated. I know that this is perfectly good English, but the phrase is so widespread, despite the fact that there are many other similar alternatives. Does anybody know whether the phrase has any specific origins?

Answer 1

From Wikipedia http://en.wikipedia.org/wiki/Q.E.D.:

Q.E.D. is an initialism of the Latin phrase quod erat demonstrandum, originating from the Greek analogous hóper édei deîxai (ὅπερ ἔδει δεῖξαι), meaning "which had to be demonstrated". The phrase is traditionally placed in its abbreviated form at the end of a mathematical proof ...

...however, translating the Greek phrase ὅπερ ἔδει δεῖξαι produces a slightly different meaning. Since the verb "δείκνυμι" also means to show or to prove, a better translation from the Greek would read, "what was required to be proved." The phrase was used by many early Greek mathematicians, including Euclid and Archimedes.

But I don't know how close this translation of Q.E.D. "what was required" is to the phrase "as desired", as desired by the OP.