Nuprl Lemma : filter-for-max

∀[A:Type]. ∀[l:A List]. ∀[m:ℤ]. ∀[g:A ⟶ ℤ].
  (||filter(λe.(g[e] =z m);l)|| ≥ 1 ) supposing ((imax-list(map(λe.g[e];l)) = m ∈ ℤ) and 0 < ||l||)


Proof




Definitions occuring in Statement :  imax-list: imax-list(L),  length: ||as||,  filter: filter(P;l),  map: map(f;as),  list: T List,  eq_int: (i =z j),  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  ge: i ≥ j ,  lambda: λx.A[x],  function: x:A ⟶ B[x],  natural_number: $n,  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  so_apply: x[s],  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  ge: i ≥ j ,  le: A ≤ B,  and: P ∧ Q,  not: ¬A,  implies: P ⇒ Q,  false: False,  prop: ℙ,  top: Top,  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  sq_type: SQType(T),  guard: {T},  l_member: (x ∈ l),  exists: ∃x:A. B[x],  cand: A c∧ B,  squash: ↓T,  nat: ℕ,  true: True,  iff: P ⇐⇒ Q,  int_seg: {i..j-},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  less_than'_wf,  length_wf,  filter_wf5,  eq_int_wf,  l_member_wf,  equal-wf-T-base,  imax-list_wf,  map-length,  int_subtype_base,  less_than_wf,  pos_length,  imax-list-member,  map_wf,  subtype_base_sq,  list_wf,  squash_wf,  true_wf,  map_length,  iff_weakening_equal,  equal_wf,  map_select,  lelt_wf,  member_filter,  select_wf,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  select_member,  assert_of_eq_int,  eta_conv,  null_nil_lemma,  btrue_wf,  member-implies-null-eq-bfalse,  btrue_neq_bfalse
Rules used in proof :  sqequalSubstitution,  sqequalRule,  sqequalReflexivity,  sqequalTransitivity,  computationStep,  isect_memberFormation,  introduction,  cut,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairEquality,  lambdaEquality,  dependent_functionElimination,  hypothesisEquality,  because_Cache,  extract_by_obid,  isectElimination,  cumulativity,  applyEquality,  functionExtensionality,  setElimination,  rename,  hypothesis,  setEquality,  natural_numberEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  independent_isectElimination,  isect_memberEquality,  voidElimination,  voidEquality,  functionEquality,  intEquality,  lambdaFormation,  instantiate,  independent_functionElimination,  baseClosed,  imageElimination,  imageMemberEquality,  universeEquality,  dependent_set_memberEquality,  independent_pairFormation,  unionElimination,  dependent_pairFormation,  int_eqEquality,  computeAll,  hyp_replacement,  applyLambdaEquality

Latex:
\mforall{}[A:Type].  \mforall{}[l:A  List].  \mforall{}[m:\mBbbZ{}].  \mforall{}[g:A  {}\mrightarrow{}  \mBbbZ{}].
    (||filter(\mlambda{}e.(g[e]  =\msubz{}  m);l)||  \mgeq{}  1  )  supposing  ((imax-list(map(\mlambda{}e.g[e];l))  =  m)  and  0  <  ||l||)



Date html generated: 2017_04_17-AM-07_50_39
Last ObjectModification: 2017_02_27-PM-04_24_30

Theory : list_1


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