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260 bytes removed ,  20:16, 3 November 2019
mathify
Miraheze>Adám Brudzewsky
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Miraheze>Adám Brudzewsky
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== History ==
== History ==


In [[A Programming Language]], prefix and suffix operations were described using the syntax <source lang=apl inline>⍺<sup>j</sup>/x</source> to take the first <source lang=apl inline>j</source> elements of vector <source lang=apl inline>x</source> and <source lang=apl inline>⍵<sup>j</sup>/x</source> for the last <source lang=apl inline>j</source> elements. This combined a use of the special prefix and suffix vectors <source lang=apl inline>⍺<sup>j</sup>(n)</source> and <source lang=apl inline>⍵<sup>j</sup>(n)</source> with [[Compress|compression]], with the length <source lang=apl inline>n</source> inferred based on the length of <source lang=apl inline>x</source>. The symbol <source lang=apl inline>↑</source> was used for vector [[Rotate]], while <source lang=apl inline>↓</source> rotated in the opposite direction.<ref>Iverson, K.E. (1962). A Programming Language. Wiley. ISBN 978-0-471-43014-8.</ref>
In [[A Programming Language]], prefix and suffix operations were described using the syntax <math>⍺^j/x</math> to take the first <math>j</math> elements of vector <math>x</math> and <math>⍵^j/x</math> for the last <math>j</math> elements. This combined a use of the special prefix and suffix vectors <math>⍺^j(n)</math> and <math>⍵^j(n)</math> with [[Compress|compression]], with the length <math>n</math> inferred based on the length of <math>x</math>. The symbol <math>↑</math> was used for vector [[Rotate]], while <math>↓</math> rotated in the opposite direction.<ref>Iverson, K.E. (1962). A Programming Language. Wiley. ISBN 978-0-471-43014-8.</ref>


Take using the symbol <source lang=apl inline>↑</source> was absent from the first version of [[APL\360]]<ref>Falkoff, A.D., and K.E. Iverson. [https://www.jsoftware.com/papers/APL360TerminalSystem.htm "The APL\360 Terminal System"]. Research Report RC-1922, IBM, 1967-10-16.</ref> but was introduced by 1968<ref>Falkoff, A.D., and K.E. Iverson, "[http://keiapl.org/archive/APL360_UsersMan_Aug1968.pdf APL\360 User's Manual]". IBM, August 1968.</ref>.
Take using the symbol <source lang=apl inline>↑</source> was absent from the first version of [[APL\360]]<ref>Falkoff, A.D., and K.E. Iverson. [https://www.jsoftware.com/papers/APL360TerminalSystem.htm "The APL\360 Terminal System"]. Research Report RC-1922, IBM, 1967-10-16.</ref> but was introduced by 1968<ref>Falkoff, A.D., and K.E. Iverson, "[http://keiapl.org/archive/APL360_UsersMan_Aug1968.pdf APL\360 User's Manual]". IBM, August 1968.</ref>.

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