Nuprl Lemma : list-max-aux-property

∀[T:Type]
  ∀f:T ⟶ ℤ. ∀L:T List.
    (↑isl(list-max-aux(x.f[x];L)))
    ∧ let n,x = outl(list-max-aux(x.f[x];L)) 
      in (x ∈ L) ∧ (f[x] = n ∈ ℤ) ∧ (∀y∈L.f[y] ≤ n) 
    supposing 0 < ||L||


Proof




Definitions occuring in Statement :  list-max-aux: list-max-aux(x.f[x];L),  l_all: (∀x∈L.P[x]),  l_member: (x ∈ l),  length: ||as||,  list: T List,  outl: outl(x),  assert: ↑b,  isl: isl(x),  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  so_apply: x[s],  le: A ≤ B,  all: ∀x:A. B[x],  and: P ∧ Q,  function: x:A ⟶ B[x],  spread: spread def,  natural_number: $n,  int: ℤ,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  guard: {T},  int_seg: {i..j-},  lelt: i ≤ j < k,  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  prop: ℙ,  decidable: Dec(P),  or: P ∨ Q,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  sq_type: SQType(T),  nat: ℕ,  ge: i ≥ j ,  le: A ≤ B,  less_than: a < b,  squash: ↓T,  assert: ↑b,  ifthenelse: if b then t else f fi ,  btrue: tt,  less_than': less_than'(a;b),  cons: [a / b],  bfalse: ff,  subtract: n - m,  list-max-aux: list-max-aux(x.f[x];L),  outl: outl(x),  isl: isl(x),  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  has-value: (a)↓,  bool: 𝔹,  unit: Unit,  it: ⋅,  uiff: uiff(P;Q),  true: True,  bnot: ¬bb,  int_iseg: {i...j},  cand: A c∧ B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  pi1: fst(t),  l_all: (∀x∈L.P[x]),  list_accum: list_accum,  firstn: firstn(n;as),  list_ind: list_ind,  nil: [],  lt_int: i <z j,  length: ||as||,  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  last: last(L),  select: L[n]
Lemmas referenced :  int_seg_properties,  full-omega-unsat,  intformand_wf,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformle_wf,  int_formula_prop_and_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_wf,  int_seg_wf,  decidable__equal_int,  subtract_wf,  subtype_base_sq,  set_subtype_base,  int_subtype_base,  intformnot_wf,  intformeq_wf,  itermSubtract_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_subtract_lemma,  decidable__le,  decidable__lt,  lelt_wf,  subtype_rel_self,  le_wf,  length_wf,  non_neg_length,  nat_properties,  less_than_wf,  member-less_than,  last-lemma-sq,  list-cases,  null_nil_lemma,  length_of_nil_lemma,  product_subtype_list,  null_cons_lemma,  length_of_cons_lemma,  false_wf,  all_wf,  list_wf,  isect_wf,  assert_wf,  isl_wf,  equal-wf-T-base,  top_wf,  list-max-aux_wf,  l_member_wf,  l_all_wf,  assert_elim,  and_wf,  equal_wf,  bfalse_wf,  btrue_neq_bfalse,  set_wf,  primrec-wf2,  nat_wf,  itermAdd_wf,  int_term_value_add_lemma,  length_wf_nat,  firstn_wf,  subtype_rel_list,  list_accum_cons_lemma,  list_accum_nil_lemma,  value-type-has-value,  int-value-type,  last_wf,  list_accum_append,  lt_int_wf,  pi1_wf,  bool_wf,  eqtt_to_assert,  assert_of_lt_int,  eqff_to_assert,  bool_cases_sqequal,  bool_subtype_base,  assert-bnot,  not_functionality_wrt_uiff,  length_firstn_eq,  iff_weakening_equal,  member_append,  cons_member,  l_all_append,  cons_wf,  nil_wf,  l_all_cons,  l_all_nil,  select_wf,  list_ind_nil_lemma,  first0
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  natural_numberEquality,  because_Cache,  hypothesisEquality,  hypothesis,  setElimination,  rename,  productElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  sqequalRule,  independent_pairFormation,  unionElimination,  applyEquality,  instantiate,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  dependent_set_memberEquality,  hypothesis_subsumption,  imageElimination,  promote_hyp,  functionEquality,  productEquality,  setEquality,  unionEquality,  cumulativity,  functionExtensionality,  addEquality,  universeEquality,  callbyvalueReduce,  equalityElimination,  imageMemberEquality,  baseClosed,  inrFormation,  inlFormation

Latex:
\mforall{}[T:Type]
    \mforall{}f:T  {}\mrightarrow{}  \mBbbZ{}.  \mforall{}L:T  List.
        (\muparrow{}isl(list-max-aux(x.f[x];L)))
        \mwedge{}  let  n,x  =  outl(list-max-aux(x.f[x];L)) 
            in  (x  \mmember{}  L)  \mwedge{}  (f[x]  =  n)  \mwedge{}  (\mforall{}y\mmember{}L.f[y]  \mleq{}  n) 
        supposing  0  <  ||L||



Date html generated: 2019_06_20-PM-01_30_41
Last ObjectModification: 2018_09_24-PM-00_40_42

Theory : list_1


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