Nuprl Lemma : twkl!-implies-dfan

∀T:Type. ((∃k:ℕ. T ~ ℕk) ⇒ WKL!(T) ⇒ Fan_d(T))


Proof




Definitions occuring in Statement :  twkl!: WKL!(T),  dfan: Fan_d(T),  equipollent: A ~ B,  int_seg: {i..j-},  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  natural_number: $n,  universe: Type
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  dfan: Fan_d(T),  dbar: dbar(T;X),  and: P ∧ Q,  tbar: tbar(T;X),  dec-predicate: Decidable(X),  ubar: ubar(T;X),  member: t ∈ T,  uall: ∀[x:A]. B[x],  decidable: Dec(P),  or: P ∨ Q,  prop: ℙ,  so_lambda: λ2x.t[x],  nat: ℕ,  so_apply: x[s],  exists: ∃x:A. B[x],  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  not: ¬A,  int_seg: {i..j-},  lelt: i ≤ j < k,  less_than: a < b,  squash: ↓T,  true: True,  upto: upto(n),  from-upto: [n, m),  ifthenelse: if b then t else f fi ,  lt_int: i <z j,  bfalse: ff,  top: Top,  subtype_rel: A ⊆r B,  uimplies: b supposing a,  guard: {T},  ge: i ≥ j ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  pi1: fst(t),  compose: f o g,  cand: A c∧ B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  sq_type: SQType(T),  equipollent: A ~ B,  biject: Bij(A;B;f),  surject: Surj(A;B;f),  twkl!: WKL!(T),  down-closed: down-closed(T;X),  R-closed: R-closed(T;x.X[x];a,b.R[a; b]),  upwd-closure: upwd-closure(T;A),  let: let,  unbounded-list-predicate: Unbounded(A),  label: ...$L... t,  uiff: uiff(P;Q),  tree-big: tree-big(T;A;n),  eff-unique-path: eff-unique-path(T;A),  sq_exists: ∃x:{A| B[x]},  is-path: is-path(A;f),  sq_stable: SqStable(P),  compat: l1 || l2
Lemmas referenced :  nil_wf,  tree-big-monotone,  dbar_wf,  list_wf,  twkl!_wf,  exists_wf,  nat_wf,  equipollent_wf,  int_seg_wf,  false_wf,  le_wf,  lelt_wf,  map_nil_lemma,  map_wf,  subtype_rel_dep_function,  int_seg_subtype_nat,  upto_wf,  all_wf,  tree-big-least,  not-tree-big,  set_wf,  tree-big_wf,  upwd-closure_wf,  not_wf,  int_seg_properties,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermAdd_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_add_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  equal_wf,  decidable__tree-big,  decidable__upwd-closure,  length_wf,  compose_wf,  less_than_wf,  squash_wf,  true_wf,  iff_weakening_equal,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  subtype_base_sq,  int_subtype_base,  add_nat_wf,  intformeq_wf,  int_formula_prop_eq_lemma,  decidable__equal_int,  non_neg_length,  equipollent-zero,  decidable__equal_equipollent,  length_wf_nat,  let_wf,  append_wf,  subtract_wf,  iseg_wf,  iseg_transitivity,  iseg_append_iff,  length-append,  map-length,  length_upto,  le_weakening2,  length_append,  subtype_rel_list,  top_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  list_extensionality,  length-map,  select-map,  iseg_select,  and_wf,  decidable__exists_length,  decidable__not,  not_over_exists,  down-closed_wf,  unbounded-list-predicate_wf,  decidable__implies,  decidable__and2,  decidable__equal_list,  imax_ub,  imax_wf,  iseg-map,  int_seg_subtype,  upto_iseg,  select_wf,  select-upto,  sq_stable_from_decidable,  decidable__exists_int_seg,  iseg_weakening,  iseg_length,  common_iseg_compat,  iseg_same_length
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  rename,  cut,  hypothesis,  dependent_functionElimination,  introduction,  extract_by_obid,  isectElimination,  cumulativity,  hypothesisEquality,  unionElimination,  functionExtensionality,  applyEquality,  functionEquality,  universeEquality,  sqequalRule,  lambdaEquality,  natural_numberEquality,  setElimination,  dependent_pairFormation,  dependent_set_memberEquality,  independent_pairFormation,  because_Cache,  imageMemberEquality,  baseClosed,  isect_memberEquality,  voidElimination,  voidEquality,  independent_isectElimination,  independent_functionElimination,  promote_hyp,  setEquality,  productEquality,  addEquality,  int_eqEquality,  intEquality,  computeAll,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  imageElimination,  instantiate,  addLevel,  levelHypothesis,  hyp_replacement,  inlFormation,  inrFormation

Latex:
\mforall{}T:Type.  ((\mexists{}k:\mBbbN{}.  T  \msim{}  \mBbbN{}k)  {}\mRightarrow{}  WKL!(T)  {}\mRightarrow{}  Fan\_d(T))



Date html generated: 2017_04_17-AM-09_38_44
Last ObjectModification: 2017_02_27-PM-05_43_56

Theory : fan-theorem


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