Effective descriptive set theory is the branch of descriptive set theory dealing with sets of reals having lightface definitions; that is, definitions that do not require an arbitrary real parameter (Moschovakis 1980). Thus effective descriptive set theory combines descriptive set theory with recursion theory.
Famous quotes containing the words effective, set and/or theory:
“[Humanity] has unquestionably one really effective weapon—laughter. Power, money, persuasion, supplication, persecution—these can lift at a colossal humbug—push it a little—weaken it a little, century by century; but only laughter can blow it to rags and atoms at a blast. Against the assault of laughter nothing can stand.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“Stripped of the cunning artifices of the tailor, and standing forth in the garb of Eden,—what a sorry set of round-shouldered, spindle-shanked, crane-necked varlets would civilized men appear!”
—Herman Melville (1819–1891)
“The theory seems to be that so long as a man is a failure he is one of God’s chillun, but that as soon as he has any luck he owes it to the Devil.”
—H.L. (Henry Lewis)