Nuprl Lemma : Troelstra-lemma

¬(∀g:ℕ ⟶ ℕ. ∃n:ℕ. ∀f:ℕ ⟶ ℕ. ((f = g ∈ (ℕn ⟶ ℕ)) ⇒ (∀x:ℕ. ((g x) = 0 ∈ ℕ)) ⇒ (∀x:ℕ. ((f x) = 0 ∈ ℕ))))


Proof




Definitions occuring in Statement :  int_seg: {i..j-},  nat: ℕ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  not: ¬A,  implies: P ⇒ Q,  apply: f a,  function: x:A ⟶ B[x],  natural_number: $n,  equal: s = t ∈ T
Definitions unfolded in proof :  not: ¬A,  implies: P ⇒ Q,  all: ∀x:A. B[x],  member: t ∈ T,  nat: ℕ,  le: A ≤ B,  and: P ∧ Q,  less_than': less_than'(a;b),  false: False,  prop: ℙ,  uall: ∀[x:A]. B[x],  exists: ∃x:A. B[x],  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  uimplies: b supposing a,  so_apply: x[s],  less_than: a < b,  true: True,  squash: ↓T,  top: Top,  int_seg: {i..j-},  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  guard: {T},  ge: i ≥ j ,  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  bfalse: ff,  sq_type: SQType(T),  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  false_wf,  le_wf,  nat_wf,  all_wf,  exists_wf,  equal_wf,  int_seg_wf,  subtype_rel_function,  int_seg_subtype_nat,  subtype_rel_self,  equal-wf-T-base,  less_than_wf,  lt_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_lt_int,  top_wf,  int_seg_properties,  nat_properties,  decidable__equal_int,  full-omega-unsat,  intformnot_wf,  intformeq_wf,  itermConstant_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_constant_lemma,  int_formula_prop_wf,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  intformand_wf,  intformless_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_subtype_base,  zero-le-nat,  squash_wf,  true_wf,  iff_weakening_equal,  decidable__le,  intformle_wf,  itermAdd_wf,  int_formula_prop_le_lemma,  int_term_value_add_lemma,  equal-wf-base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  hypothesis,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  lambdaEquality,  dependent_set_memberEquality,  natural_numberEquality,  sqequalRule,  independent_pairFormation,  introduction,  extract_by_obid,  isectElimination,  hypothesisEquality,  productElimination,  functionEquality,  setElimination,  rename,  applyEquality,  because_Cache,  independent_isectElimination,  baseClosed,  lessCases,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  isect_memberFormation,  axiomSqEquality,  isect_memberEquality,  voidElimination,  voidEquality,  imageElimination,  independent_functionElimination,  functionExtensionality,  unionElimination,  equalityElimination,  approximateComputation,  dependent_pairFormation,  intEquality,  promote_hyp,  instantiate,  cumulativity,  int_eqEquality,  universeEquality,  addEquality,  applyLambdaEquality

Latex:
\mneg{}(\mforall{}g:\mBbbN{}  {}\mrightarrow{}  \mBbbN{}.  \mexists{}n:\mBbbN{}.  \mforall{}f:\mBbbN{}  {}\mrightarrow{}  \mBbbN{}.  ((f  =  g)  {}\mRightarrow{}  (\mforall{}x:\mBbbN{}.  ((g  x)  =  0))  {}\mRightarrow{}  (\mforall{}x:\mBbbN{}.  ((f  x)  =  0))))



Date html generated: 2019_06_20-PM-02_49_34
Last ObjectModification: 2018_08_20-PM-09_32_57

Theory : fan-theorem


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