Nuprl Lemma : filter-equal

∀[T:Type]. ∀[P:T ⟶ 𝔹]. ∀[L1,L2:T List].
  (filter(P;L1) = filter(P;L2) ∈ (T List)) supposing 
     ((∀i:ℕ||L1||. ((L1[i] = L2[i] ∈ T) ∨ ((¬↑(P L1[i])) ∧ (¬↑(P L2[i]))))) and 
     (||L1|| = ||L2|| ∈ ℤ))


Proof




Definitions occuring in Statement :  select: L[n],  length: ||as||,  filter: filter(P;l),  list: T List,  int_seg: {i..j-},  assert: ↑b,  bool: 𝔹,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  not: ¬A,  or: P ∨ Q,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n,  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  true: True,  assert: ↑b,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  bfalse: ff,  ifthenelse: if b then t else f fi ,  btrue: tt,  unit: Unit,  bool: 𝔹,  uall: ∀[x:A]. B[x],  member: t ∈ T,  all: ∀x:A. B[x],  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  uimplies: b supposing a,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  and: P ∧ Q,  prop: ℙ,  or: P ∨ Q,  select: L[n],  nil: [],  it: ⋅,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  int_seg: {i..j-},  lelt: i ≤ j < k,  cons: [a / b],  colength: colength(L),  guard: {T},  so_lambda: λ2x.t[x],  so_apply: x[s],  sq_type: SQType(T),  le: A ≤ B,  subtype_rel: A ⊆r B,  decidable: Dec(P),  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  uiff: uiff(P;Q),  nat_plus: ℕ+
Lemmas referenced :  select-cons,  squash_wf,  true_wf,  add-subtract-cancel,  bool_subtype_base,  iff_imp_equal_bool,  le_int_wf,  bfalse_wf,  iff_functionality_wrt_iff,  iff_weakening_uiff,  assert_of_le_int,  iff_weakening_equal,  assert_of_bnot,  eqff_to_assert,  uiff_transitivity,  eqtt_to_assert,  nat_properties,  full-omega-unsat,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  ge_wf,  istype-less_than,  list-cases,  length_of_nil_lemma,  stuck-spread,  istype-base,  filter_nil_lemma,  nil_wf,  int_seg_wf,  int_seg_properties,  product_subtype_list,  colength-cons-not-zero,  subtract-1-ge-0,  subtype_base_sq,  intformeq_wf,  int_formula_prop_eq_lemma,  set_subtype_base,  int_subtype_base,  spread_cons_lemma,  length_of_cons_lemma,  filter_cons_lemma,  non_neg_length,  itermAdd_wf,  int_term_value_add_lemma,  length_wf,  colength_wf_list,  decidable__le,  intformnot_wf,  int_formula_prop_not_lemma,  istype-le,  decidable__equal_int,  subtract_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  le_wf,  add-is-int-iff,  false_wf,  select_wf,  cons_wf,  decidable__lt,  istype-assert,  istype-nat,  list_wf,  bool_wf,  istype-universe,  istype-false,  add_nat_plus,  length_wf_nat,  nat_plus_properties,  equal-wf-T-base,  assert_wf,  bnot_wf,  not_wf,  assert_elim,  not_assert_elim,  btrue_neq_bfalse
Rules used in proof :  imageMemberEquality,  cumulativity,  equalityElimination,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  introduction,  cut,  thin,  Error :lambdaFormation_alt,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  hypothesis,  setElimination,  rename,  intWeakElimination,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  Error :dependent_pairFormation_alt,  Error :lambdaEquality_alt,  int_eqEquality,  dependent_functionElimination,  Error :isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  Error :universeIsType,  axiomEquality,  Error :isectIsTypeImplies,  Error :inhabitedIsType,  Error :functionIsTypeImplies,  unionElimination,  baseClosed,  because_Cache,  Error :functionIsType,  equalityTransitivity,  equalitySymmetry,  productElimination,  Error :equalityIstype,  sqequalBase,  promote_hyp,  hypothesis_subsumption,  instantiate,  applyLambdaEquality,  addEquality,  applyEquality,  Error :dependent_set_memberEquality_alt,  imageElimination,  baseApply,  closedConclusion,  intEquality,  pointwiseFunctionality,  Error :unionIsType,  Error :productIsType,  universeEquality

Latex:
\mforall{}[T:Type].  \mforall{}[P:T  {}\mrightarrow{}  \mBbbB{}].  \mforall{}[L1,L2:T  List].
    (filter(P;L1)  =  filter(P;L2))  supposing 
          ((\mforall{}i:\mBbbN{}||L1||.  ((L1[i]  =  L2[i])  \mvee{}  ((\mneg{}\muparrow{}(P  L1[i]))  \mwedge{}  (\mneg{}\muparrow{}(P  L2[i])))))  and 
          (||L1||  =  ||L2||))



Date html generated: 2019_06_20-PM-02_13_14
Last ObjectModification: 2019_06_20-PM-02_08_13

Theory : list_1


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