Nuprl Lemma : append_split2

∀[T:Type]
  ∀L:T List
    ∀[P:ℕ||L|| ⟶ ℙ]
      ((∀x:ℕ||L||. Dec(P x))
      ⇒ (∀i,j:ℕ||L||.  ((P i) ⇒ P j supposing i < j))
      ⇒ (∃L_1,L_2:T List. ((L = (L_1 @ L_2) ∈ (T List)) ∧ (∀i:ℕ||L||. (P i ⇐⇒ ||L_1|| ≤ i)))))


Proof




Definitions occuring in Statement :  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,  le: A ≤ B,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  and: P ∧ Q,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  and: P ∧ Q,  subtype_rel: A ⊆r B,  int_seg: {i..j-},  so_lambda: λ2x.t[x],  lelt: i ≤ j < k,  guard: {T},  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  less_than: a < b,  squash: ↓T,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  implies: P ⇒ Q,  not: ¬A,  top: Top,  so_apply: x[s],  cand: A c∧ B,  int_iseg: {i...j},  true: True,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  le: A ≤ B,  nat: ℕ,  less_than': less_than'(a;b),  ge: i ≥ j ,  label: ...$L... t
Lemmas referenced :  length_wf,  all_wf,  int_seg_wf,  not_wf,  int_seg_properties,  decidable__lt,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  lelt_wf,  decidable__exists_int_seg,  decidable__and2,  decidable__all_int_seg,  decidable__not,  less_than_wf,  decidable_wf,  list_wf,  firstn_wf,  nth_tl_wf,  equal_wf,  squash_wf,  true_wf,  append_firstn_lastn,  subtype_rel_sets,  le_wf,  decidable__le,  intformle_wf,  int_formula_prop_le_lemma,  iff_weakening_equal,  less_than'_wf,  append_wf,  length-append,  length_firstn,  exists_wf,  iff_wf,  decidable__equal_int,  itermConstant_wf,  intformeq_wf,  int_term_value_constant_lemma,  int_formula_prop_eq_lemma,  nil_wf,  append_back_nil,  nat_wf,  false_wf,  subtract_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  set_wf,  primrec-wf2,  nat_properties
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  natural_numberEquality,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  cumulativity,  hypothesisEquality,  hypothesis,  lambdaEquality,  productEquality,  applyEquality,  functionExtensionality,  because_Cache,  sqequalRule,  setElimination,  rename,  dependent_set_memberEquality,  productElimination,  independent_pairFormation,  dependent_functionElimination,  unionElimination,  imageElimination,  independent_isectElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  isect_memberFormation,  lambdaFormation,  instantiate,  independent_functionElimination,  functionEquality,  universeEquality,  isectEquality,  equalityTransitivity,  equalitySymmetry,  setEquality,  applyLambdaEquality,  imageMemberEquality,  baseClosed,  independent_pairEquality,  axiomEquality,  hyp_replacement,  hypothesis_subsumption

Latex:
\mforall{}[T:Type]
    \mforall{}L:T  List
        \mforall{}[P:\mBbbN{}||L||  {}\mrightarrow{}  \mBbbP{}]
            ((\mforall{}x:\mBbbN{}||L||.  Dec(P  x))
            {}\mRightarrow{}  (\mforall{}i,j:\mBbbN{}||L||.    ((P  i)  {}\mRightarrow{}  P  j  supposing  i  <  j))
            {}\mRightarrow{}  (\mexists{}L$_{1}$,L$_{2}$:T  List.  ((L  =  (L$_{1\mbackslash{}\000Cff7d$  @  L$_{2}$))  \mwedge{}  (\mforall{}i:\mBbbN{}||L||.  (P  i  \mLeftarrow{}{}\mRightarrow{}  ||L$_{1}$||  \mleq{}  i\000C)))))



Date html generated: 2017_04_14-AM-09_25_30
Last ObjectModification: 2017_02_27-PM-04_00_30

Theory : list_1


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