Step
*
of Lemma
filter-commutes
∀[T:Type]. ∀[P1,P2:T ⟶ 𝔹]. ∀[L:T List].  (filter(P1;filter(P2;L)) ~ filter(P2;filter(P1;L)))
BY
{ ObviousListInduction }
Latex:
Latex:
\mforall{}[T:Type].  \mforall{}[P1,P2:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].    (filter(P1;filter(P2;L))  \msim{}  filter(P2;filter(P1;L)))
By
Latex:
ObviousListInduction
Home
Index