Argument-ending letters (3 letters)

{ Answer }

QED

{ Related Clues }

Argument closer
Argument ender
End of a demonstration?
End of a proof
Ending letters
Geometer's postscript
Geometer's P.S.
Geometric postscript
Letters from a mathematician
Letters to a mathematician
Letters of triumph
Logical conclusion
Logician's abbr.
Logician's letters
Math abbr.
Math finale
Math initials
Math proof
Proof closer
Proof ender
Proof finale
Proof letters
Proof's end
Proof's ending
"Proved!" letters
Proved, in math.
"And that proves it"
Triumphant end?
Abbr. at the end of a proof
Abbr. in a math textbook
Finale for a geom. lesson
Geometric sign-off
Letters after a proof
Letters at the end of a proof
Mathematical proof letters
Mathematician's "ta-da!"
Mathematician's "ta-da"
Proof-ending letters
Proof finale letters
Latin abbr. used in math
Letters seen during proofreading?
Logician's triumphant sign-off
Theorem prover's sign-off
Abbr. after a series of equations, maybe

{ Tags }

abbr, after, argument, end, ender, ending, euclidean, finale, geometers, initials, letters, logical, logicians, math, mathematicians, off, proof, proved, qed, seen, sign

{ Notes }

The answer QED is seen frequently, appearing about once every 160 puzzles.

{ Definition }

QED as a noun:

1. (quantum electrodynamics, QED) = a relativistic quantum theory of the electromagnetic interactions of photons and electrons and muons