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: List outl: outl(x) assert: b isl: isl(x) less_than: a < b uimplies: 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: universe: Type equal: 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: supposing a not: ¬A implies:  Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top prop: decidable: Dec(P) or: P ∨ Q subtype_rel: A ⊆B so_lambda: λ2x.t[x] so_apply: x[s] sq_type: SQType(T) nat: ge: i ≥  le: A ≤ B less_than: a < b squash: T assert: b ifthenelse: if then else fi  btrue: tt less_than': less_than'(a;b) cons: [a b] bfalse: ff subtract: m list-max-aux: list-max-aux(x.f[x];L) outl: outl(x) isl: isl(x) so_lambda: λ2y.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: c∧ B iff: ⇐⇒ Q rev_implies:  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 <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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