T /T/ 1. [from LISP terminology for `true'] Yes. Used in reply to a
   question (particularly one asked using {The -P convention}). In LISP,
   the constant T means `true', among other things. Some Lisp hackers use
   `T' and `NIL' instead of `Yes' and `No' almost reflexively. This
   sometimes causes misunderstandings. When a waiter or flight attendant
   asks whether a hacker wants coffee, he may absently respond `T', meaning
   that he wants coffee; but of course he will be brought a cup of tea
   instead. Fortunately, most hackers (particularly those who frequent
   Chinese restaurants) like tea at least as well as coffee -- so it is not
   that big a problem. 2. See {time T} (also {since time T equals minus  infinity}). 3. [techspeak] In transaction-processing circles, an
   abbreviation for the noun `transaction'. 4. [Purdue] Alternate spelling
   of {tee}. 5. A dialect of {LISP} developed at Yale. (There is an
   intended allusion to NIL, "New Implementation of Lisp", another dialect
   of Lisp developed for the {VAX})