Nuprl Lemma : rational-approx-property

∀x:ℝ. ∀n:ℕ+.  (|x - (x within 1/n)| ≤ (r1/r(n)))


Proof




Definitions occuring in Statement :  rational-approx: (x within 1/n),  rdiv: (x/y),  rleq: x ≤ y,  rabs: |x|,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  nat_plus: ℕ+,  all: ∀x:A. B[x],  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  rational-approx: (x within 1/n),  member: t ∈ T,  uall: ∀[x:A]. B[x],  int_nzero: ℤ-o,  nat_plus: ℕ+,  nequal: a ≠ b ∈ T ,  not: ¬A,  implies: P ⇒ Q,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  top: Top,  and: P ∧ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  real: ℝ,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  decidable: Dec(P),  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  true: True,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  rdiv: (x/y),  itermConstant: "const",  req_int_terms: t1 ≡ t2,  nat: ℕ
Lemmas referenced :  nat_plus_wf,  real_wf,  rabs_wf,  rsub_wf,  int-rdiv_wf,  nat_plus_properties,  satisfiable-full-omega-tt,  intformand_wf,  intformeq_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  intformless_wf,  int_formula_prop_and_lemma,  int_formula_prop_eq_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_wf,  equal-wf-base,  int_subtype_base,  nequal_wf,  int-to-real_wf,  rdiv_wf,  rless-int,  decidable__lt,  intformnot_wf,  int_formula_prop_not_lemma,  rless_wf,  rmul_preserves_rleq,  rmul_wf,  radd_wf,  rinv_wf2,  rminus_wf,  rleq_functionality,  rabs_functionality,  rsub_functionality,  req_weakening,  int-rdiv-req,  req_transitivity,  real_term_polynomial,  itermSubtract_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_mul_lemma,  real_term_value_var_lemma,  req-iff-rsub-is-0,  rmul_functionality,  itermAdd_wf,  itermMinus_wf,  real_term_value_add_lemma,  real_term_value_minus_lemma,  radd_functionality,  rminus-rdiv,  squash_wf,  true_wf,  rneq_wf,  rminus-int,  rmul-rinv,  rmul-int,  rmul-assoc,  req_wf,  rabs-int,  iff_weakening_equal,  req-int,  absval_wf,  nat_wf,  equal_wf,  absval_pos,  decidable__le,  intformle_wf,  int_formula_prop_le_lemma,  le_wf,  req_inversion,  rabs-rmul,  real-approx
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  dependent_set_memberEquality,  multiplyEquality,  natural_numberEquality,  setElimination,  rename,  independent_isectElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  sqequalRule,  independent_pairFormation,  computeAll,  baseApply,  closedConclusion,  baseClosed,  applyEquality,  because_Cache,  inrFormation,  productElimination,  independent_functionElimination,  unionElimination,  minusEquality,  imageMemberEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  universeEquality

Latex:
\mforall{}x:\mBbbR{}.  \mforall{}n:\mBbbN{}\msupplus{}.    (|x  -  (x  within  1/n)|  \mleq{}  (r1/r(n)))



Date html generated: 2017_10_03-AM-08_40_44
Last ObjectModification: 2017_07_28-AM-07_31_25

Theory : reals


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