Nuprl Lemma : apply-alist-count-repeats

∀[T:Type]. ∀[eq:EqDecider(T)]. ∀[x:T]. ∀[L:T List].
  (apply-alist(eq;count-repeats(L,eq);x) = if x ∈b L then inl ||filter(λy.(eq y x);L)|| else inr ⋅  fi  ∈ (ℕ+?))


Proof




Definitions occuring in Statement :  count-repeats: count-repeats(L,eq),  apply-alist: apply-alist(eq;L;x),  length: ||as||,  deq-member: x ∈b L,  filter: filter(P;l),  list: T List,  deq: EqDecider(T),  nat_plus: ℕ+,  ifthenelse: if b then t else f fi ,  it: ⋅,  uall: ∀[x:A]. B[x],  unit: Unit,  apply: f a,  lambda: λx.A[x],  inr: inr x ,  inl: inl x,  union: left + right,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  implies: P ⇒ Q,  guard: {T},  all: ∀x:A. B[x],  exposed-bfalse: exposed-bfalse,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  iff: P ⇐⇒ Q,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  false: False,  not: ¬A,  rev_implies: P ⇐ Q,  prop: ℙ,  nat_plus: ℕ+,  deq: EqDecider(T),  eqof: eqof(d),  rev_uimplies: rev_uimplies(P;Q),  so_apply: x[s1;s2;s3],  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2],  so_lambda: λ2x y.t[x; y],  top: Top,  apply-alist: apply-alist(eq;L;x),  count-repeats: count-repeats(L,eq),  satisfiable_int_formula: satisfiable_int_formula(fmla),  le: A ≤ B,  subtract: n - m,  decidable: Dec(P),  true: True,  less_than': less_than'(a;b),  less_than: a < b,  squash: ↓T,  subtype_rel: A ⊆r B
Lemmas referenced :  last_induction,  list_wf,  deq_wf,  equal_wf,  nat_plus_wf,  unit_wf2,  apply-alist_wf,  count-repeats_wf,  deq-member_wf,  eqtt_to_assert,  assert-deq-member,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_wf,  bool_subtype_base,  assert-bnot,  l_member_wf,  it_wf,  length_wf,  filter_wf5,  member-exists2,  member_filter,  safe-assert-deq,  less_than_wf,  list_ind_nil_lemma,  filter_nil_lemma,  deq_member_nil_lemma,  list_accum_nil_lemma,  equal-wf-T-base,  cons_member,  length_of_nil_lemma,  length_of_cons_lemma,  member_append,  append_back_nil,  length-singleton,  length-append,  int_formula_prop_wf,  int_term_value_var_lemma,  int_term_value_add_lemma,  int_term_value_constant_lemma,  int_formula_prop_less_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  itermAdd_wf,  itermConstant_wf,  intformless_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  filter_cons_lemma,  filter_append_sq,  iff_weakening_equal,  le-add-cancel,  add-zero,  add-associates,  add_functionality_wrt_le,  add-commutes,  minus-one-mul-top,  zero-add,  minus-one-mul,  minus-add,  condition-implies-le,  less-iff-le,  not-lt-2,  false_wf,  decidable__lt,  apply-updated-alist,  true_wf,  squash_wf,  list_accum_cons_lemma,  top_wf,  subtype_rel_list,  list_accum_append,  nil_wf,  cons_wf,  append_wf,  and_wf,  assert_wf,  not_wf,  l_all_iff,  filter_is_nil,  or_wf,  member_singleton
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  thin,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  sqequalRule,  independent_functionElimination,  hypothesis,  dependent_functionElimination,  Error :universeIsType,  Error :isect_memberEquality_alt,  axiomEquality,  because_Cache,  universeEquality,  Error :lambdaEquality_alt,  unionEquality,  Error :inhabitedIsType,  Error :lambdaFormation_alt,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  independent_isectElimination,  Error :inlEquality_alt,  Error :dependent_pairFormation_alt,  Error :equalityIsType1,  promote_hyp,  instantiate,  cumulativity,  voidElimination,  Error :inrEquality_alt,  Error :dependent_set_memberEquality_alt,  setElimination,  rename,  applyEquality,  Error :setIsType,  independent_pairFormation,  natural_numberEquality,  inrEquality,  voidEquality,  isect_memberEquality,  inrFormation,  inlFormation,  applyLambdaEquality,  hyp_replacement,  computeAll,  int_eqEquality,  inlEquality,  minusEquality,  intEquality,  addEquality,  baseClosed,  imageMemberEquality,  dependent_set_memberEquality,  levelHypothesis,  equalityUniverse,  imageElimination,  dependent_pairFormation,  setEquality,  lambdaEquality,  lambdaFormation,  addLevel,  orFunctionality

Latex:
\mforall{}[T:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[x:T].  \mforall{}[L:T  List].
    (apply-alist(eq;count-repeats(L,eq);x)
    =  if  x  \mmember{}\msubb{}  L  then  inl  ||filter(\mlambda{}y.(eq  y  x);L)||  else  inr  \mcdot{}    fi  )



Date html generated: 2019_06_20-PM-01_54_46
Last ObjectModification: 2018_10_05-AM-10_55_37

Theory : decidable!equality


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