1. [n]  the 25th letter of the Roman alphabet
2. [n]  a silvery metallic element that is common in rare-earth minerals; used in magnesium and aluminum alloys

y
Songs Of Mississippi John Hurt

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1. \Y\ (w[imac]).
   Y, the twenty-fifth letter of the English alphabet, at the
   beginning of a word or syllable, except when a prefix (see
   Y-), is usually a fricative vocal consonant; as a prefix, and
   usually in the middle or at the end of a syllable, it is a
   vowel. See Guide to Pronunciation, [sect][sect] 145, 178-9,
   272.
   Note: It derives its form from the Latin Y, which is from the
         Greek [Upsilon], originally the same letter as V.
         Etymologically, it is most nearly related to u, i, o,
         and j. g; as in full, fill, AS. fyllan; E. crypt,
         grotto; young, juvenile; day, AS. d[ae]g. See {U}, {I},
         and {J}, {G}.
   Note: Y has been called the Pythagorean letter, because the
         Greek letter [Upsilon] was taken represent the sacred
         triad, formed by the duad proceeding from the monad;
         and also because it represents the dividing of the
         paths of vice and virtue in the development of human
         life.
   

2. \Y\ (w[imac]), n.; pl. {Y's} (w[imac]z) or {Ys}.
   Something shaped like the letter Y; a forked piece resembling
   in form the letter Y. Specifically:
   (a) One of the forked holders for supporting the telescope of
       a leveling instrument, or the axis of a theodolite; a
       wye.
   (b) A forked or bifurcated pipe fitting.
   (c) (Railroads) A portion of track consisting of two
       diverging tracks connected by a cross track.
   {Y level} (Surv.), an instrument for measuring differences of
      level by means of a telescope resting in Y's.
   {Y moth} (Zo["o]l.), a handsome European noctuid moth {Plusia
      gamma}) which has a bright, silvery mark, shaped like the
      letter Y, on each of the fore wings. Its larva, which is
      green with five dorsal white species, feeds on the
      cabbage, turnip, bean, etc. Called also {gamma moth}, and
      {silver Y}.
   

3. \Y\ ([imac]), pron.
   I. [Obs.] --King Horn. Wyclif.
   

4. \Y-\, or I- \I-\ . [OE. y-, i-, AS. ge-, akin to D. & G. ge-,
   OHG. gi-, ga-, Goth. ga-, and perhaps to Latin con-;
   originally meaning, together. Cf. {Com-}, {Aware}, {Enough},
   {Handiwork}, {Ywis}.]
   A prefix of obscure meaning, originally used with verbs,
   adverbs, adjectives, nouns, and pronouns. In the Middle
   English period, it was little employed except with verbs,
   being chiefly used with past participles, though occasionally
   with the infinitive Ycleped, or yclept, is perhaps the only
   word not entirely obsolete which shows this use.
         That no wight mighte it see neither yheere. --Chaucer.
         Neither to ben yburied nor ybrent.       --Chaucer.
   Note: Some examples of Chaucer's use of this prefix are; ibe,
         ibeen, icaught, ycome, ydo, idoon, ygo, iproved,
         ywrought. It inough, enough, it is combined with an
         adjective. Other examples are in the Vocabulary.
         Spenser and later writers frequently employed this
         prefix when affecting an archaic style, and sometimes
         used it incorrectly.
   

1. General purpose language syntactically like RATFOR, semantically like C. Lacks structures and pointers. Used as a source language for Jack W. Davidson and Christopher W. Fraser's peephole optimiser which inspired GCC RTL and other optimisation ideas.

. It is a copy of the original distribution from the University of Arizona during the early 80's, totally unsupported.

["The Y Programming Language", D.R. Hanson, SIGPLAN Notices 16(2):59-68 (Feb 1981)].

[Jack W. Davidson and Christopher W. Fraser, "The Design and Application of a Retargetable Peephole Optimiser", TOPLAS, Apr. 1980].

[Jack W. Davidson, "Simplifying Code Through Peephole Optimisation" Technical Report TR81-19, The University of Arizona, Tucson, AZ, 1981].

[Jack W. Davidson and Christopher W. Fraser, "Register Allocation and Exhaustive Peephole Optimisation" Software-Practice and Experience, Sep. 1984].

2. See fixed point combinator.