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Step * of Lemma fset-absorption2

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[a,b:fset(T)].  (a ⋂ a ⋃ b = a ∈ fset(T))
BY
{ (Auto
   THEN (UsingVars [`eq'] (BLemma `fset-extensionality`) THENA Auto)
   THEN (D 0 THENA Auto)
   THEN RWW "member-fset-union member-fset-intersection" 0
   THEN Auto) }

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Latex:

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Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[a,b:fset(T)].    (a  \mcap{}  a  \mcup{}  b  =  a)


By

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Latex:
(Auto
  THEN  (UsingVars  [`eq']  (BLemma  `fset-extensionality`)  THENA  Auto)
  THEN  (D  0  THENA  Auto)
  THEN  RWW  "member-fset-union  member-fset-intersection"  0
  THEN  Auto)

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