Nuprl Lemma : cantor-interval-length

∀[a,b:ℝ]. ∀[n:ℕ]. ∀[f:ℕn ⟶ 𝔹].  (((snd(cantor-interval(a;b;f;n))) - fst(cantor-interval(a;b;f;n))) = (2^n * b - a)/3^n)


Proof




Definitions occuring in Statement :  cantor-interval: cantor-interval(a;b;f;n),  int-rdiv: (a)/k1,  int-rmul: k1 * a,  rsub: x - y,  req: x = y,  real: ℝ,  exp: i^n,  int_seg: {i..j-},  nat: ℕ,  bool: 𝔹,  uall: ∀[x:A]. B[x],  pi1: fst(t),  pi2: snd(t),  function: x:A ⟶ B[x],  natural_number: $n
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  nat: ℕ,  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  uimplies: b supposing a,  not: ¬A,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  all: ∀x:A. B[x],  top: Top,  and: P ∧ Q,  prop: ℙ,  cantor-interval: cantor-interval(a;b;f;n),  decidable: Dec(P),  or: P ∨ Q,  pi2: snd(t),  pi1: fst(t),  int_nzero: ℤ-o,  nequal: a ≠ b ∈ T ,  int_seg: {i..j-},  lelt: i ≤ j < k,  subtype_rel: A ⊆r B,  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,  sq_stable: SqStable(P),  squash: ↓T,  nat_plus: ℕ+,  less_than: a < b,  rneq: x ≠ y,  guard: {T},  rless: x < y,  sq_exists: ∃x:A [B[x]],  so_lambda: λ2x.t[x],  so_apply: x[s],  rev_uimplies: rev_uimplies(P;Q),  sq_type: SQType(T),  lt_int: i <z j,  ifthenelse: if b then t else f fi ,  btrue: tt,  bool: 𝔹,  unit: Unit,  it: ⋅,  bfalse: ff,  bnot: ¬bb,  assert: ↑b,  rdiv: (x/y),  req_int_terms: t1 ≡ t2
Lemmas referenced :  nat_properties,  full-omega-unsat,  intformand_wf,  intformle_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  istype-int,  int_formula_prop_and_lemma,  istype-void,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  ge_wf,  istype-less_than,  req_witness,  rsub_wf,  cantor-interval_wf,  decidable__le,  intformnot_wf,  int_formula_prop_not_lemma,  istype-le,  int-rdiv_wf,  exp_wf3,  intformeq_wf,  int_formula_prop_eq_lemma,  nequal_wf,  int-rmul_wf,  exp_wf2,  subtract-1-ge-0,  istype-nat,  real_wf,  int_seg_wf,  int_seg_properties,  req_weakening,  subtype_rel_function,  bool_wf,  subtract_wf,  int_seg_subtype,  istype-false,  not-le-2,  condition-implies-le,  add-associates,  minus-add,  minus-one-mul,  add-swap,  minus-one-mul-top,  add-mul-special,  zero-mul,  add-zero,  add-commutes,  le-add-cancel2,  subtype_rel_self,  sq_stable__req,  ifthenelse_wf,  lt_int_wf,  itermSubtract_wf,  int_term_value_subtract_lemma,  decidable__lt,  radd_wf,  exp_step,  exp-positive-stronger,  rless-int,  nat_plus_properties,  rmul_preserves_req,  rless_wf,  int-to-real_wf,  req_wf,  rdiv_wf,  rmul_wf,  rminus_wf,  itermMultiply_wf,  itermAdd_wf,  itermMinus_wf,  rinv_wf2,  int_term_value_mul_lemma,  rneq_functionality,  rmul-int,  rneq-int,  set_subtype_base,  less_than_wf,  int_subtype_base,  subtype_base_sq,  decidable__equal_int,  req-iff-rsub-is-0,  nat_plus_inc_int_nzero,  primrec-unroll,  exp0_lemma,  req_functionality,  req_transitivity,  int-rdiv-one,  int-rmul-one,  eqtt_to_assert,  assert_of_lt_int,  eqff_to_assert,  bool_cases_sqequal,  bool_subtype_base,  assert-bnot,  iff_weakening_uiff,  assert_wf,  int-rdiv-req,  rsub_functionality,  rdiv_functionality,  int-rmul-req,  radd_functionality,  rmul_functionality,  rmul-rinv3,  real_polynomial_null,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_var_lemma,  real_term_value_add_lemma,  real_term_value_minus_lemma,  real_term_value_const_lemma,  req_inversion,  rminus_functionality,  rinv-mul-as-rdiv,  rinv-of-rmul,  int-rinv-cancel
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation_alt,  introduction,  cut,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  setElimination,  rename,  intWeakElimination,  lambdaFormation_alt,  natural_numberEquality,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation_alt,  lambdaEquality_alt,  int_eqEquality,  dependent_functionElimination,  isect_memberEquality_alt,  voidElimination,  sqequalRule,  independent_pairFormation,  universeIsType,  isectIsTypeImplies,  inhabitedIsType,  functionIsTypeImplies,  dependent_set_memberEquality_alt,  unionElimination,  productElimination,  equalityIstype,  equalityTransitivity,  equalitySymmetry,  because_Cache,  baseClosed,  sqequalBase,  intEquality,  functionIsType,  applyEquality,  addEquality,  minusEquality,  multiplyEquality,  productEquality,  independent_pairEquality,  productIsType,  imageMemberEquality,  imageElimination,  inrFormation_alt,  closedConclusion,  baseApply,  instantiate,  cumulativity,  equalityElimination,  promote_hyp

Latex:
\mforall{}[a,b:\mBbbR{}].  \mforall{}[n:\mBbbN{}].  \mforall{}[f:\mBbbN{}n  {}\mrightarrow{}  \mBbbB{}].
    (((snd(cantor-interval(a;b;f;n)))  -  fst(cantor-interval(a;b;f;n)))  =  (2\^{}n  *  b  -  a)/3\^{}n)



Date html generated: 2019_10_30-AM-07_37_38
Last ObjectModification: 2018_12_16-PM-04_42_33

Theory : reals


Home Index