Nuprl Lemma : remove-repeats-filter

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[P:T ⟶ 𝔹]. ∀[L:T List].
  (remove-repeats(eq;filter(P;L)) = filter(P;remove-repeats(eq;L)) ∈ (T List))


Proof




Definitions occuring in Statement :  remove-repeats: remove-repeats(eq;L),  filter: filter(P;l),  list: T List,  deq: EqDecider(T),  bool: 𝔹,  uall: ∀[x:A]. B[x],  function: x:A ⟶ B[x],  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  prop: ℙ,  uimplies: b supposing a,  all: ∀x:A. B[x],  implies: P ⇒ Q,  top: Top,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  ifthenelse: if b then t else f fi ,  squash: ↓T,  true: True,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  deq: EqDecider(T),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  not: ¬A,  eqof: eqof(d),  band: p ∧b q
Lemmas referenced :  list_induction,  equal_wf,  list_wf,  remove-repeats_wf,  filter_wf5,  subtype_rel_dep_function,  bool_wf,  l_member_wf,  set_wf,  subtype_rel_self,  filter_nil_lemma,  remove_repeats_nil_lemma,  nil_wf,  filter_cons_lemma,  remove_repeats_cons_lemma,  eqtt_to_assert,  cons_wf,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  filter-filter,  band_wf,  bnot_wf,  iff_weakening_equal,  iff_imp_equal_bool,  assert_elim,  and_wf,  not_assert_elim,  btrue_neq_bfalse,  assert_wf,  not_wf,  iff_transitivity,  eqof_wf,  iff_weakening_uiff,  assert_of_band,  assert_of_bnot,  safe-assert-deq,  iff_wf,  deq_wf,  band_commutes
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  thin,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  lambdaEquality,  cumulativity,  hypothesis,  because_Cache,  applyEquality,  setEquality,  independent_isectElimination,  setElimination,  rename,  lambdaFormation,  independent_functionElimination,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  functionExtensionality,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  imageElimination,  natural_numberEquality,  imageMemberEquality,  baseClosed,  dependent_pairFormation,  promote_hyp,  instantiate,  independent_pairFormation,  addLevel,  levelHypothesis,  dependent_set_memberEquality,  applyLambdaEquality,  productEquality,  impliesFunctionality,  andLevelFunctionality,  impliesLevelFunctionality,  axiomEquality,  functionEquality,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L:T  List].
    (remove-repeats(eq;filter(P;L))  =  filter(P;remove-repeats(eq;L)))



Date html generated: 2017_04_17-AM-09_10_35
Last ObjectModification: 2017_02_27-PM-05_19_19

Theory : decidable!equality


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