Nuprl Lemma : mapfilter-wf

[T,U:Type]. ∀[L:T List]. ∀[P:T ⟶ 𝔹]. ∀[f:{x:T| (x ∈ L) ∧ (↑P[x])}  ⟶ U].  (mapfilter(f;P;L) ∈ List)


Proof




Definitions occuring in Statement :  mapfilter: mapfilter(f;P;L) l_member: (x ∈ l) list: List assert: b bool: 𝔹 uall: [x:A]. B[x] so_apply: x[s] and: P ∧ Q member: t ∈ T set: {x:A| B[x]}  function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  mapfilter: mapfilter(f;P;L) uall: [x:A]. B[x] member: t ∈ T so_apply: x[s] and: P ∧ Q prop: subtype_rel: A ⊆B so_lambda: λ2x.t[x] uimplies: supposing a all: x:A. B[x]
Lemmas referenced :  map_wf and_wf l_member_wf assert_wf filter_type subtype_rel_dep_function bool_wf subtype_rel_self set_wf list-subtype subtype_rel_list list_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity cut lemma_by_obid sqequalHypSubstitution isectElimination thin setEquality hypothesisEquality hypothesis applyEquality cumulativity because_Cache sqequalRule lambdaEquality independent_isectElimination setElimination rename lambdaFormation equalityTransitivity equalitySymmetry productEquality dependent_set_memberEquality independent_pairFormation functionEquality universeEquality isect_memberFormation introduction axiomEquality isect_memberEquality

Latex:
\mforall{}[T,U:Type].  \mforall{}[L:T  List].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[f:\{x:T|  (x  \mmember{}  L)  \mwedge{}  (\muparrow{}P[x])\}    {}\mrightarrow{}  U].
    (mapfilter(f;P;L)  \mmember{}  U  List)



Date html generated: 2016_05_14-PM-01_29_12
Last ObjectModification: 2015_12_26-PM-05_22_16

Theory : list_1


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