Nuprl Lemma : filter_wf

[T:Type]. ∀[l:T List]. ∀[P:T ⟶ 𝔹].  (filter(P;l) ∈ List)


Proof




Definitions occuring in Statement :  filter: filter(P;l) list: List bool: 𝔹 uall: [x:A]. B[x] member: t ∈ T function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T filter: filter(P;l)
Lemmas referenced :  reduce_wf list_wf ifthenelse_wf cons_wf nil_wf bool_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity Error :isect_memberFormation_alt,  introduction cut sqequalRule extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis lambdaEquality applyEquality axiomEquality equalityTransitivity equalitySymmetry Error :functionIsType,  Error :universeIsType,  isect_memberEquality functionEquality because_Cache universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[l:T  List].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].    (filter(P;l)  \mmember{}  T  List)



Date html generated: 2019_06_20-PM-00_39_13
Last ObjectModification: 2018_09_26-PM-02_05_47

Theory : list_0


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