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Step * of Lemma mapfilter-as-reduce2

∀[L,p,f:Top].  (mapfilter(f;p;L) ~ reduce(λx,a. if p x then [f x / a] else a fi ;[];L))
BY
{ (RepUR ``mapfilter`` 0 THEN ListIndSq `L' THEN RWO "map-ifthenelse" 0 THEN Reduce 0 THEN Auto) }

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Latex:

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Latex:
\mforall{}[L,p,f:Top].    (mapfilter(f;p;L)  \msim{}  reduce(\mlambda{}x,a.  if  p  x  then  [f  x  /  a]  else  a  fi  ;[];L))


By

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Latex:
(RepUR  ``mapfilter``  0  THEN  ListIndSq  `L'  THEN  RWO  "map-ifthenelse"  0  THEN  Reduce  0  THEN  Auto)

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