Nuprl Lemma : append_split

∀[T:Type]
  ∀L:T List
    ∀[P:T ⟶ ℙ]
      ((∀x:ℕ||L||. Dec(P L[x]))
      ⇒ (∀i,j:ℕ||L||.  ((P L[i]) ⇒ P L[j] supposing i < j))
      ⇒ (∃L1,L2:T List
           (((L = (L1 @ L2) ∈ (T List)) ∧ (∀i:ℕ||L1||. (¬(P L1[i]))) ∧ (∀i:ℕ||L2||. (P L2[i])))
           ∧ (∀x∈L.(P x) ⇒ (x ∈ L2)))))


Proof




Definitions occuring in Statement :  l_all: (∀x∈L.P[x]),  l_member: (x ∈ l),  select: L[n],  length: ||as||,  append: as @ bs,  list: T List,  int_seg: {i..j-},  less_than: a < b,  decidable: Dec(P),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  prop: ℙ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  prop: ℙ,  implies: P ⇒ Q,  int_seg: {i..j-},  uimplies: b supposing a,  guard: {T},  lelt: i ≤ j < k,  and: P ∧ Q,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T,  so_apply: x[s],  subtype_rel: A ⊆r B,  select: L[n],  nil: [],  it: ⋅,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  append: as @ bs,  so_lambda: so_lambda(x,y,z.t[x; y; z]),  so_apply: x[s1;s2;s3],  cand: A c∧ B,  ge: i ≥ j ,  le: A ≤ B,  uiff: uiff(P;Q),  subtract: n - m,  less_than': less_than'(a;b),  nat_plus: ℕ+,  true: True,  cons: [a / b],  iff: P ⇐⇒ Q,  sq_type: SQType(T),  rev_implies: P ⇐ Q,  l_all: (∀x∈L.P[x])
Lemmas referenced :  list_induction,  uall_wf,  all_wf,  int_seg_wf,  length_wf,  decidable_wf,  select_wf,  int_seg_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,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  less_than_wf,  exists_wf,  list_wf,  equal_wf,  append_wf,  length-append,  not_wf,  l_all_wf,  l_member_wf,  length_of_nil_lemma,  stuck-spread,  base_wf,  length_of_cons_lemma,  nil_wf,  list_ind_nil_lemma,  l_all_nil,  equal-wf-base-T,  intformeq_wf,  int_formula_prop_eq_lemma,  l_all_wf_nil,  cons_wf,  non_neg_length,  itermAdd_wf,  int_term_value_add_lemma,  add-member-int_seg2,  subtract_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  lelt_wf,  select_cons_tl_sq,  member-less_than,  select-cons-tl,  add-subtract-cancel,  false_wf,  add_nat_plus,  length_wf_nat,  nat_plus_wf,  nat_plus_properties,  add-is-int-iff,  squash_wf,  true_wf,  select-cons-hd,  select_append_front,  iff_weakening_equal,  length_zero,  decidable__equal_int,  subtype_base_sq,  int_subtype_base,  select_cons_tl,  l_all_cons,  cons_member,  list_ind_cons_lemma
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesisEquality,  sqequalRule,  lambdaEquality,  functionEquality,  because_Cache,  universeEquality,  natural_numberEquality,  hypothesis,  applyEquality,  functionExtensionality,  setElimination,  rename,  independent_isectElimination,  productElimination,  dependent_functionElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  imageElimination,  isectEquality,  productEquality,  applyLambdaEquality,  setEquality,  independent_functionElimination,  baseClosed,  equalityTransitivity,  equalitySymmetry,  addEquality,  dependent_set_memberEquality,  imageMemberEquality,  pointwiseFunctionality,  promote_hyp,  baseApply,  closedConclusion,  hyp_replacement,  inlFormation,  inrFormation

Latex:
\mforall{}[T:Type]
    \mforall{}L:T  List
        \mforall{}[P:T  {}\mrightarrow{}  \mBbbP{}]
            ((\mforall{}x:\mBbbN{}||L||.  Dec(P  L[x]))
            {}\mRightarrow{}  (\mforall{}i,j:\mBbbN{}||L||.    ((P  L[i])  {}\mRightarrow{}  P  L[j]  supposing  i  <  j))
            {}\mRightarrow{}  (\mexists{}L1,L2:T  List
                      (((L  =  (L1  @  L2))  \mwedge{}  (\mforall{}i:\mBbbN{}||L1||.  (\mneg{}(P  L1[i])))  \mwedge{}  (\mforall{}i:\mBbbN{}||L2||.  (P  L2[i])))
                      \mwedge{}  (\mforall{}x\mmember{}L.(P  x)  {}\mRightarrow{}  (x  \mmember{}  L2)))))



Date html generated: 2017_10_01-AM-08_34_35
Last ObjectModification: 2017_07_26-PM-04_25_29

Theory : list!


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