Nuprl Lemma : member-filter

∀[T:Type]. ∀P:T ⟶ 𝔹. ∀L:T List. ∀x:{x:T| ↑P[x]} .  ((x ∈ filter(λx.P[x];L)) ⇐⇒ (x ∈ L))


Proof




Definitions occuring in Statement :  l_member: (x ∈ l),  filter: filter(P;l),  list: T List,  assert: ↑b,  bool: 𝔹,  uall: ∀[x:A]. B[x],  so_apply: x[s],  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  set: {x:A| B[x]} ,  lambda: λx.A[x],  function: x:A ⟶ B[x],  universe: Type
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  prop: ℙ,  so_apply: x[s],  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  false: False,  rev_implies: P ⇐ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  squash: ↓T,  true: True
Lemmas referenced :  list_induction,  assert_wf,  iff_wf,  l_member_wf,  filter_type,  list_wf,  filter_nil_lemma,  null_nil_lemma,  btrue_wf,  member-implies-null-eq-bfalse,  nil_wf,  istype-assert,  btrue_neq_bfalse,  filter_cons_lemma,  eqtt_to_assert,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_wf,  bool_subtype_base,  assert-bnot,  istype-universe,  equal_functionality_wrt_subtype_rel2,  subtype_rel_set_simple,  cons_member,  cons_wf,  assert_elim,  equal_wf,  and_wf,  not_assert_elim,  or_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  lambdaFormation_alt,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality_alt,  functionEquality,  setEquality,  applyEquality,  hypothesis,  universeIsType,  setElimination,  rename,  independent_functionElimination,  dependent_functionElimination,  Error :memTop,  independent_pairFormation,  dependent_set_memberEquality_alt,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  voidElimination,  because_Cache,  setIsType,  inhabitedIsType,  unionElimination,  equalityElimination,  productElimination,  dependent_pairFormation_alt,  equalityIstype,  promote_hyp,  instantiate,  cumulativity,  functionIsType,  productIsType,  universeEquality,  inlFormation_alt,  inrFormation_alt,  unionIsType,  applyLambdaEquality,  imageMemberEquality,  baseClosed,  imageElimination,  inlFormation,  natural_numberEquality,  dependent_set_memberEquality,  inrFormation,  lambdaFormation,  lambdaEquality

Latex:
\mforall{}[T:Type].  \mforall{}P:T  {}\mrightarrow{}  \mBbbB{}.  \mforall{}L:T  List.  \mforall{}x:\{x:T|  \muparrow{}P[x]\}  .    ((x  \mmember{}  filter(\mlambda{}x.P[x];L))  \mLeftarrow{}{}\mRightarrow{}  (x  \mmember{}  L))



Date html generated: 2020_05_19-PM-09_37_46
Last ObjectModification: 2020_01_04-PM-07_57_53

Theory : list_0


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