Nuprl Lemma : mem_iff_count_nzero

∀s:DSet. ∀a:|s|. ∀bs:|s| List.  (↑(a ∈b bs) ⇐⇒ (a #∈ bs) > 0)


Proof




Definitions occuring in Statement :  count: a #∈ as,  mem: a ∈b as,  list: T List,  assert: ↑b,  gt: i > j,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  natural_number: $n,  dset: DSet,  set_car: |p|
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  dset: DSet,  so_apply: x[s],  implies: P ⇒ Q,  top: Top,  assert: ↑b,  ifthenelse: if b then t else f fi ,  bfalse: ff,  prop: ℙ,  iff: P ⇐⇒ Q,  and: P ∧ Q,  false: False,  rev_implies: P ⇐ Q,  gt: i > j,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  infix_ap: x f y,  or: P ∨ Q,  uiff: uiff(P;Q),  uimplies: b supposing a,  b2i: b2i(b),  ge: i ≥ j ,  decidable: Dec(P),  le: A ≤ B,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  not: ¬A,  guard: {T},  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt
Lemmas referenced :  list_induction,  iff_wf,  assert_wf,  mem_wf,  gt_wf,  count_wf,  list_wf,  set_car_wf,  mem_nil_lemma,  count_nil_lemma,  mem_cons_lemma,  count_cons_lemma,  dset_wf,  false_wf,  bor_wf,  set_eq_wf,  or_wf,  equal_wf,  b2i_wf,  iff_transitivity,  iff_weakening_uiff,  assert_of_bor,  assert_of_dset_eq,  bool_wf,  equal-wf-T-base,  non_neg_length,  count_bounds,  decidable__lt,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  intformle_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_le_lemma,  int_formula_prop_wf,  bnot_wf,  not_wf,  add-is-int-iff,  uiff_transitivity,  eqtt_to_assert,  eqff_to_assert,  assert_of_bnot
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  because_Cache,  sqequalRule,  lambdaEquality,  dependent_functionElimination,  hypothesisEquality,  hypothesis,  natural_numberEquality,  setElimination,  rename,  independent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  imageElimination,  productElimination,  applyEquality,  addEquality,  addLevel,  impliesFunctionality,  orFunctionality,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  baseClosed,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  computeAll,  inlFormation,  inrFormation,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  equalityElimination

Latex:
\mforall{}s:DSet.  \mforall{}a:|s|.  \mforall{}bs:|s|  List.    (\muparrow{}(a  \mmember{}\msubb{}  bs)  \mLeftarrow{}{}\mRightarrow{}  (a  \#\mmember{}  bs)  >  0)



Date html generated: 2017_10_01-AM-09_56_21
Last ObjectModification: 2017_03_03-PM-00_57_55

Theory : list_2


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