Nuprl Lemma : Coquand-fan-theorem

∀[T:Type]
  (finite-type(T)
  ⇒ (∀p:wfd-tree(T). ∀A:n:ℕ ⟶ (ℕn ⟶ T) ⟶ ℙ.
        ((∀n:ℕ. ∀s:ℕn ⟶ T.  ((A n s) ⇒ (∀m:{n...}. ∀t:ℕm ⟶ T.  ((t = s ∈ (ℕn ⟶ T)) ⇒ (A m t)))))
        ⇒ (p|A)
        ⇒ (∃N:ℕ. ∀m:{N...}. ∀as:ℕm ⟶ T.  (A m as)))))


Proof




Definitions occuring in Statement :  tree-bars: (p|A),  finite-type: finite-type(T),  wfd-tree: wfd-tree(T),  int_upper: {i...},  int_seg: {i..j-},  nat: ℕ,  uall: ∀[x:A]. B[x],  prop: ℙ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: 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],  implies: P ⇒ Q,  wfd-tree: wfd-tree(T),  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  nat: ℕ,  prop: ℙ,  int_upper: {i...},  uimplies: b supposing a,  and: P ∧ Q,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  guard: {T},  ge: i ≥ j ,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  uiff: uiff(P;Q),  bfalse: ff,  tree-bars: (p|A),  Wsup: Wsup(a;b),  int_seg: {i..j-},  lelt: i ≤ j < k,  sq_type: SQType(T),  bnot: ¬bb,  assert: ↑b,  predicate-shift: A_x,  seq-append: seq-append(n;m;s1;s2),  less_than: a < b,  true: True,  squash: ↓T,  finite-type: finite-type(T),  pi1: fst(t),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  l_exists: (∃x∈L. P[x]),  nat_plus: ℕ+,  select: L[n],  cons: [a / b],  surject: Surj(A;B;f),  seq-single: seq-single(t),  subtract: n - m,  nequal: a ≠ b ∈ T ,  cand: A c∧ B
Lemmas referenced :  W-induction,  bool_wf,  ifthenelse_wf,  all_wf,  nat_wf,  int_seg_wf,  int_upper_wf,  equal_wf,  subtype_rel_dep_function,  int_seg_subtype,  false_wf,  int_upper_properties,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  int_upper_subtype_nat,  tree-bars_wf,  exists_wf,  W_wf,  eqtt_to_assert,  le_wf,  int_seg_properties,  intformless_wf,  itermConstant_wf,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  predicate-shift_wf,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  finite-type_wf,  decidable__equal_int,  intformeq_wf,  int_formula_prop_eq_lemma,  itermAdd_wf,  int_term_value_add_lemma,  seq-append_wf,  seq-single_wf,  lt_int_wf,  assert_of_lt_int,  top_wf,  less_than_wf,  lelt_wf,  subtract_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  decidable__lt,  imax-list-ub,  cons_wf,  map_wf,  upto_wf,  length_of_cons_lemma,  non_neg_length,  map_length,  length_wf,  add_nat_plus,  length_wf_nat,  nat_plus_wf,  nat_plus_properties,  add-is-int-iff,  select_wf,  add-associates,  add-swap,  add-commutes,  zero-add,  not-le-2,  condition-implies-le,  minus-add,  minus-one-mul,  minus-one-mul-top,  add_functionality_wrt_le,  le-add-cancel,  eq_int_wf,  assert_of_eq_int,  int_subtype_base,  neg_assert_of_eq_int,  add-member-int_seg2,  l_exists_iff,  l_member_wf,  cons_member,  member_map,  equal-wf-T-base,  member_upto2,  int_seg_subtype_nat
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  lambdaFormation,  cut,  thin,  instantiate,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  cumulativity,  hypothesis,  sqequalRule,  lambdaEquality,  hypothesisEquality,  universeEquality,  voidEquality,  functionEquality,  applyEquality,  natural_numberEquality,  setElimination,  rename,  because_Cache,  functionExtensionality,  independent_isectElimination,  independent_pairFormation,  dependent_functionElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  computeAll,  equalityElimination,  productElimination,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  dependent_set_memberEquality,  applyLambdaEquality,  promote_hyp,  addLevel,  hyp_replacement,  levelHypothesis,  addEquality,  lessCases,  sqequalAxiom,  imageMemberEquality,  baseClosed,  imageElimination,  pointwiseFunctionality,  baseApply,  closedConclusion,  minusEquality,  int_eqReduceTrueSq,  int_eqReduceFalseSq,  setEquality,  productEquality,  inrFormation

Latex:
\mforall{}[T:Type]
    (finite-type(T)
    {}\mRightarrow{}  (\mforall{}p:wfd-tree(T).  \mforall{}A:n:\mBbbN{}  {}\mrightarrow{}  (\mBbbN{}n  {}\mrightarrow{}  T)  {}\mrightarrow{}  \mBbbP{}.
                ((\mforall{}n:\mBbbN{}.  \mforall{}s:\mBbbN{}n  {}\mrightarrow{}  T.    ((A  n  s)  {}\mRightarrow{}  (\mforall{}m:\{n...\}.  \mforall{}t:\mBbbN{}m  {}\mrightarrow{}  T.    ((t  =  s)  {}\mRightarrow{}  (A  m  t)))))
                {}\mRightarrow{}  (p|A)
                {}\mRightarrow{}  (\mexists{}N:\mBbbN{}.  \mforall{}m:\{N...\}.  \mforall{}as:\mBbbN{}m  {}\mrightarrow{}  T.    (A  m  as)))))



Date html generated: 2017_04_17-AM-09_39_01
Last ObjectModification: 2017_02_27-PM-05_36_19

Theory : fan-theorem


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