Nuprl Lemma : bexists_iff_exists_nth

∀s:DSet. ∀f:|s| ⟶ 𝔹. ∀as:|s| List.  (↑∃b x(:|s|) ∈ as. f[x] ⇐⇒ ∃n:ℕ||as||. (↑f[as[n]]))


Proof




Definitions occuring in Statement :  mon_for: For{g} x ∈ as. f[x],  select: L[n],  length: ||as||,  list: T List,  int_seg: {i..j-},  assert: ↑b,  bool: 𝔹,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  natural_number: $n,  bor_mon: <𝔹,∨b>,  dset: DSet,  set_car: |p|
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  uall: ∀[x:A]. B[x],  dset: DSet,  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  so_apply: x[s],  int_seg: {i..j-},  uimplies: b supposing a,  guard: {T},  lelt: i ≤ j < k,  and: P ∧ Q,  decidable: Dec(P),  or: P ∨ Q,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  prop: ℙ,  less_than: a < b,  squash: ↓T,  select: L[n],  nil: [],  it: ⋅,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  bor_mon: <𝔹,∨b>,  grp_id: e,  pi2: snd(t),  pi1: fst(t),  assert: ↑b,  ifthenelse: if b then t else f fi ,  bfalse: ff,  grp_op: *,  infix_ap: x f y,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  ge: i ≥ j ,  le: A ≤ B,  less_than': less_than'(a;b),  nat_plus: ℕ+,  true: True,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  subtract: n - m
Lemmas referenced :  list_wf,  set_car_wf,  bool_wf,  dset_wf,  list_induction,  iff_wf,  assert_wf,  mon_for_wf,  bor_mon_wf,  exists_wf,  int_seg_wf,  length_wf,  select_wf,  int_seg_properties,  decidable__le,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  mon_for_nil_lemma,  length_of_nil_lemma,  stuck-spread,  istype-base,  mon_for_cons_lemma,  length_of_cons_lemma,  iff_weakening_uiff,  bor_wf,  or_wf,  assert_of_bor,  cons_wf,  non_neg_length,  itermAdd_wf,  int_term_value_add_lemma,  istype-false,  add_nat_plus,  length_wf_nat,  less_than_wf,  nat_plus_properties,  add-is-int-iff,  intformeq_wf,  int_formula_prop_eq_lemma,  false_wf,  le_wf,  assert_functionality_wrt_uiff,  select_cons_hd,  add-member-int_seg2,  subtract_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  add-subtract-cancel,  select_cons_tl,  add-associates,  add-swap,  add-commutes,  zero-add,  decidable__equal_int
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  universeIsType,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setElimination,  rename,  hypothesisEquality,  hypothesis,  functionIsType,  sqequalRule,  lambdaEquality_alt,  dependent_functionElimination,  applyEquality,  because_Cache,  natural_numberEquality,  independent_isectElimination,  productElimination,  unionElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  independent_pairFormation,  imageElimination,  baseClosed,  inhabitedIsType,  promote_hyp,  productIsType,  addEquality,  unionIsType,  dependent_set_memberEquality_alt,  imageMemberEquality,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  pointwiseFunctionality,  baseApply,  closedConclusion,  equalityIsType1,  inlFormation_alt,  inrFormation_alt

Latex:
\mforall{}s:DSet.  \mforall{}f:|s|  {}\mrightarrow{}  \mBbbB{}.  \mforall{}as:|s|  List.    (\muparrow{}\mexists{}b  x(:|s|)  \mmember{}  as.  f[x]  \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbN{}||as||.  (\muparrow{}f[as[n]]))



Date html generated: 2019_10_16-PM-01_03_22
Last ObjectModification: 2018_10_08-AM-11_16_52

Theory : list_2


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