Nuprl Lemma : filter_wf2

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


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  filter: filter(P;l),  list: T List,  bool: 𝔹,  uall: ∀[x:A]. B[x],  member: t ∈ T,  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  prop: ℙ,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  all: ∀x:A. B[x],  uimplies: b supposing a
Lemmas referenced :  l_member_wf,  bool_wf,  list_wf,  filter_wf5,  list-subtype,  subtype_rel_dep_function,  set_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  hypothesis,  sqequalRule,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  functionEquality,  setEquality,  hypothesisEquality,  lemma_by_obid,  isectElimination,  thin,  isect_memberEquality,  because_Cache,  universeEquality,  applyEquality,  lambdaEquality,  lambdaFormation,  setElimination,  rename,  independent_isectElimination

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



Date html generated: 2016_05_14-AM-06_39_48
Last ObjectModification: 2015_12_26-PM-00_31_52

Theory : list_0


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