Nuprl Lemma : cantor-to-interval-onto-lemma

∀a,b:ℝ.
  ∀x:ℝ. ∀n:ℕ. ∀f:{f:ℕn ⟶ 𝔹| x ∈ [fst(cantor-interval(a;b;f;n)), snd(cantor-interval(a;b;f;n))]} .
    ∃g:{g:ℕn + 1 ⟶ 𝔹| x ∈ [fst(cantor-interval(a;b;g;n + 1)), snd(cantor-interval(a;b;g;n + 1))]} . (g = f ∈ (ℕn ⟶ 𝔹))\000C 
  supposing a < b


Proof




Definitions occuring in Statement :  cantor-interval: cantor-interval(a;b;f;n),  rccint: [l, u],  i-member: r ∈ I,  rless: x < y,  real: ℝ,  int_seg: {i..j-},  nat: ℕ,  bool: 𝔹,  uimplies: b supposing a,  pi1: fst(t),  pi2: snd(t),  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  set: {x:A| B[x]} ,  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  uimplies: b supposing a,  member: t ∈ T,  uall: ∀[x:A]. B[x],  prop: ℙ,  int_seg: {i..j-},  lelt: i ≤ j < k,  and: P ∧ Q,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  decidable: Dec(P),  or: P ∨ Q,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  so_apply: x[s],  guard: {T},  sq_type: SQType(T),  nat: ℕ,  rless: x < y,  sq_exists: ∃x:A [B[x]],  nat_plus: ℕ+,  pi1: fst(t),  pi2: snd(t),  le: A ≤ B,  less_than': less_than'(a;b),  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  uiff: uiff(P;Q),  subtract: n - m,  true: True,  real: ℝ,  sq_stable: SqStable(P),  squash: ↓T,  ge: i ≥ j ,  cantor-interval: cantor-interval(a;b;f;n),  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  bfalse: ff,  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  nequal: a ≠ b ∈ T ,  int_nzero: ℤ-o,  i-member: r ∈ I,  rccint: [l, u]
Lemmas referenced :  cantor-middle-third-lemma,  rless_wf,  real_wf,  int_seg_properties,  full-omega-unsat,  intformand_wf,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformle_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_wf,  int_seg_wf,  decidable__equal_int,  subtract_wf,  subtype_base_sq,  set_subtype_base,  lelt_wf,  int_subtype_base,  intformnot_wf,  intformeq_wf,  itermSubtract_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_subtract_lemma,  decidable__le,  decidable__lt,  istype-le,  istype-less_than,  subtype_rel_self,  nat_plus_properties,  guard_wf,  all_wf,  bool_wf,  isect_wf,  i-member_wf,  rccint_wf,  cantor-interval_wf,  sq_exists_wf,  equal_wf,  subtype_rel_function,  int_seg_subtype,  istype-false,  not-le-2,  condition-implies-le,  minus-add,  minus-one-mul,  add-swap,  minus-one-mul-top,  add-mul-special,  zero-mul,  add-zero,  add-associates,  add-commutes,  le-add-cancel,  sq_stable__less_than,  itermAdd_wf,  int_term_value_add_lemma,  primrec-wf2,  nat_properties,  istype-nat,  sq_stable__i-member,  pi1_wf_top,  pi2_wf,  eq_int_wf,  eqtt_to_assert,  assert_of_eq_int,  member_rccint_lemma,  eqff_to_assert,  bool_cases_sqequal,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  primrec-unroll,  add-subtract-cancel,  subtype_rel_product,  top_wf,  cantor-interval-rless,  btrue_wf,  not-equal-2,  rleq_wf,  ifthenelse_wf,  lt_int_wf,  int-rdiv_wf,  nequal_wf,  radd_wf,  int-rmul_wf,  assert_of_lt_int,  iff_weakening_uiff,  assert_wf,  less_than_wf,  bfalse_wf,  sq_stable__rleq,  subtype_rel_set
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation_alt,  isect_memberFormation_alt,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  because_Cache,  universeIsType,  isectElimination,  hypothesis,  inhabitedIsType,  natural_numberEquality,  setElimination,  rename,  productElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  unionElimination,  applyEquality,  instantiate,  cumulativity,  intEquality,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  dependent_set_memberEquality_alt,  productIsType,  hypothesis_subsumption,  functionIsType,  functionEquality,  closedConclusion,  equalityIstype,  addEquality,  productEquality,  minusEquality,  multiplyEquality,  imageMemberEquality,  baseClosed,  imageElimination,  setIsType,  equalityElimination,  promote_hyp,  dependent_set_memberFormation_alt,  independent_pairEquality,  spreadEquality,  sqequalBase,  dependent_pairEquality_alt,  functionExtensionality,  hyp_replacement

Latex:
\mforall{}a,b:\mBbbR{}.
    \mforall{}x:\mBbbR{}.  \mforall{}n:\mBbbN{}.  \mforall{}f:\{f:\mBbbN{}n  {}\mrightarrow{}  \mBbbB{}|  x  \mmember{}  [fst(cantor-interval(a;b;f;n)),  snd(cantor-interval(a;b;f;n))]\}  .
        \mexists{}g:\{g:\mBbbN{}n  +  1  {}\mrightarrow{}  \mBbbB{}|  x  \mmember{}  [fst(cantor-interval(a;b;g;n  +  1)),  snd(cantor-interval(a;b;g;n  +  1))]\} 
          (g  =  f) 
    supposing  a  <  b



Date html generated: 2019_10_30-AM-07_40_35
Last ObjectModification: 2018_12_11-AM-11_12_08

Theory : reals


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