Nuprl Lemma : dense-in-interval-implies

∀I:Interval
  ∀[X:{a:ℝ| a ∈ I}  ⟶ ℙ]
    (dense-in-interval(I;X)
    ⇒ (∃u,v:{a:ℝ| a ∈ I} . u ≠ v)
    ⇒ (∀a:{a:ℝ| a ∈ I} . ∃x:ℕ ⟶ {a:ℝ| a ∈ I} . ((∀n:ℕ. (X (x n))) ∧ lim n→∞.x n = a)))


Proof




Definitions occuring in Statement :  dense-in-interval: dense-in-interval(I;X),  i-member: r ∈ I,  interval: Interval,  converges-to: lim n→∞.x[n] = y,  rneq: x ≠ y,  real: ℝ,  nat: ℕ,  uall: ∀[x:A]. B[x],  prop: ℙ,  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  implies: P ⇒ Q,  and: P ∧ Q,  set: {x:A| B[x]} ,  apply: f a,  function: x:A ⟶ B[x]
Definitions unfolded in proof :  so_apply: x[s],  so_lambda: λ2x.t[x],  subtype_rel: A ⊆r B,  cand: A c∧ B,  uimplies: b supposing a,  guard: {T},  squash: ↓T,  sq_stable: SqStable(P),  and: P ∧ Q,  dense-in-interval: dense-in-interval(I;X),  rneq: x ≠ y,  prop: ℙ,  or: P ∨ Q,  member: t ∈ T,  exists: ∃x:A. B[x],  implies: P ⇒ Q,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  true: True,  less_than': less_than'(a;b),  less_than: a < b,  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  rev_uimplies: rev_uimplies(P;Q),  uiff: uiff(P;Q),  top: Top,  not: ¬A,  false: False,  req_int_terms: t1 ≡ t2,  rge: x ≥ y,  pi1: fst(t),  nat: ℕ,  nequal: a ≠ b ∈ T ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  decidable: Dec(P),  assert: ↑b,  bnot: ¬bb,  sq_type: SQType(T),  bfalse: ff,  it: ⋅,  unit: Unit,  bool: 𝔹,  btrue: tt,  ifthenelse: if b then t else f fi ,  subtract: n - m,  eq_int: (i =z j),  primrec: primrec(n;b;c),  exp: i^n,  nat_plus: ℕ+,  le: A ≤ B,  rnonneg: rnonneg(x),  rleq: x ≤ y,  ge: i ≥ j ,  rdiv: (x/y),  int_nzero: ℤ-o
Lemmas referenced :  interval_wf,  dense-in-interval_wf,  exists_wf,  set_wf,  real_wf,  rless_wf,  i-member_wf,  rleq_weakening_rless,  sq_stable__i-member,  i-member-between,  rneq_wf,  rneq-cases,  rless-int,  int-to-real_wf,  rdiv_wf,  rmul_wf,  rsub_wf,  rabs_wf,  rleq_wf,  ravg_wf,  ravg-between,  sq_stable_rneq,  ravg_comm,  rsub_functionality,  rabs_functionality,  req_inversion,  req_weakening,  rleq_functionality,  ravg-dist,  real_term_value_var_lemma,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_polynomial_null,  rabs-of-nonneg,  rabs-difference-symmetry,  req-iff-rsub-is-0,  itermVar_wf,  itermConstant_wf,  itermSubtract_wf,  rleq_weakening,  rsub_functionality_wrt_rleq,  rleq_weakening_equal,  rleq_functionality_wrt_implies,  real_term_value_add_lemma,  itermAdd_wf,  radd-zero,  radd_wf,  radd-preserves-rleq,  subtype_rel_sets,  all_wf,  equal_wf,  converges-to_wf,  nat_wf,  int_seg_wf,  primrec_wf,  primrec-wf2,  less_than_wf,  le_wf,  int_formula_prop_wf,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_subtract_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  intformless_wf,  intformle_wf,  intformnot_wf,  intformand_wf,  full-omega-unsat,  decidable__le,  subtract_wf,  neg_assert_of_eq_int,  assert-bnot,  bool_subtype_base,  subtype_base_sq,  bool_cases_sqequal,  eqff_to_assert,  assert_of_eq_int,  eqtt_to_assert,  bool_wf,  eq_int_wf,  primrec-unroll,  exp-positive,  exp0_lemma,  nat_plus_wf,  nat_plus_properties,  exp_wf2,  less_than'_wf,  ge_wf,  nat_properties,  real_term_value_mul_lemma,  real_term_value_minus_lemma,  rmul-identity1,  rinv1,  rmul_functionality,  req_transitivity,  itermMultiply_wf,  rinv_wf2,  itermMinus_wf,  rminus_wf,  int_formula_prop_eq_lemma,  intformeq_wf,  nequal_wf,  true_wf,  exp_wf3,  int_nzero-rational,  int-subtype-rationals,  equal_functionality_wrt_subtype_rel2,  int_subtype_base,  rationals_wf,  equal-wf-base,  not_functionality_wrt_implies,  rneq-int,  rinv-mul-as-rdiv,  rmul-rinv3,  rmul_preserves_rleq,  exp_wf_nat_plus,  req-int-fractions,  one-mul,  exp_step,  exp-positive-stronger,  rmul_assoc,  simple-converges-to
Rules used in proof :  cumulativity,  functionEquality,  inrFormation,  universeEquality,  lambdaEquality,  setEquality,  functionExtensionality,  applyEquality,  productEquality,  inlFormation,  independent_pairFormation,  dependent_set_memberEquality,  independent_isectElimination,  imageElimination,  baseClosed,  imageMemberEquality,  sqequalRule,  isectElimination,  dependent_pairFormation,  unionElimination,  hypothesisEquality,  independent_functionElimination,  hypothesis,  because_Cache,  rename,  setElimination,  dependent_functionElimination,  extract_by_obid,  introduction,  thin,  productElimination,  sqequalHypSubstitution,  cut,  isect_memberFormation,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  natural_numberEquality,  voidEquality,  voidElimination,  isect_memberEquality,  intEquality,  int_eqEquality,  approximateComputation,  equalitySymmetry,  equalityTransitivity,  promote_hyp,  instantiate,  equalityElimination,  axiomEquality,  minusEquality,  independent_pairEquality,  intWeakElimination,  addLevel,  closedConclusion,  baseApply

Latex:
\mforall{}I:Interval
    \mforall{}[X:\{a:\mBbbR{}|  a  \mmember{}  I\}    {}\mrightarrow{}  \mBbbP{}]
        (dense-in-interval(I;X)
        {}\mRightarrow{}  (\mexists{}u,v:\{a:\mBbbR{}|  a  \mmember{}  I\}  .  u  \mneq{}  v)
        {}\mRightarrow{}  (\mforall{}a:\{a:\mBbbR{}|  a  \mmember{}  I\}  .  \mexists{}x:\mBbbN{}  {}\mrightarrow{}  \{a:\mBbbR{}|  a  \mmember{}  I\}  .  ((\mforall{}n:\mBbbN{}.  (X  (x  n)))  \mwedge{}  lim  n\mrightarrow{}\minfty{}.x  n  =  a)))



Date html generated: 2017_10_03-AM-10_19_34
Last ObjectModification: 2017_07_31-AM-11_30_20

Theory : reals


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