| Some definitions of interest. |
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compose | Def (f o g)(x) == f(g(x)) |
| | Thm* A,B,C:Type, f:(B![](FONT/dash.png) C), g:(A![](FONT/dash.png) B). f o g A![](FONT/dash.png) C |
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filter | Def filter(P;l) == reduce( a,v. if P(a) [a / v] else v fi;nil;l) |
| | Thm* T:Type, P:(T![](FONT/dash.png) ![](FONT/then_med.png) ), l:T List. filter(P;l) T List |
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map | Def map(f;as) == Case of as; nil nil ; a.as' [(f(a)) / map(f;as')]
Def (recursive) |
| | Thm* A,B:Type, f:(A![](FONT/dash.png) B), l:A List. map(f;l) B List |
| | Thm* A,B:Type, f:(A![](FONT/dash.png) B), l:A List . map(f;l) B List![](FONT/plus.png) |