Nuprl Lemma : req-iff-rabs-rleq

∀x,y:ℝ.  (x = y ⇐⇒ ∀m:ℕ+. (|x - y| ≤ (r1/r(m))))


Proof




Definitions occuring in Statement :  rdiv: (x/y),  rleq: x ≤ y,  rabs: |x|,  rsub: x - y,  req: x = y,  int-to-real: r(n),  real: ℝ,  nat_plus: ℕ+,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  and: P ∧ Q,  implies: P ⇒ Q,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  rev_implies: P ⇐ Q,  so_lambda: λ2x.t[x],  nat_plus: ℕ+,  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  so_apply: x[s],  subtype_rel: A ⊆r B,  true: True,  uiff: uiff(P;Q),  rev_uimplies: rev_uimplies(P;Q),  absval: |i|,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  rdiv: (x/y),  squash: ↓T,  sq_exists: ∃x:{A| B[x]},  rless: x < y
Lemmas referenced :  nat_plus_wf,  req_wf,  all_wf,  rleq_wf,  rabs_wf,  rsub_wf,  rdiv_wf,  int-to-real_wf,  rless-int,  nat_plus_properties,  decidable__lt,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  rless_wf,  real_wf,  absval_wf,  rinv_wf2,  rmul_wf,  rleq-int-fractions2,  decidable__le,  intformle_wf,  itermMultiply_wf,  int_formula_prop_le_lemma,  int_term_value_mul_lemma,  rleq_functionality,  rabs_functionality,  rsub_functionality,  req_weakening,  uiff_transitivity2,  real_term_polynomial,  itermSubtract_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_var_lemma,  req-iff-rsub-is-0,  req_transitivity,  real_term_value_mul_lemma,  rinv-as-rdiv,  squash_wf,  true_wf,  rabs-int,  rless_transitivity1,  rless_irreflexivity,  small-reciprocal-real,  req-iff-not-rneq,  rneq-iff-rabs,  rneq_wf,  not_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  cut,  introduction,  extract_by_obid,  hypothesis,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  lambdaEquality,  natural_numberEquality,  setElimination,  rename,  because_Cache,  independent_isectElimination,  inrFormation,  dependent_functionElimination,  productElimination,  independent_functionElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  applyEquality,  minusEquality,  multiplyEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  impliesFunctionality,  addLevel,  lemma_by_obid,  dependent_set_memberEquality

Latex:
\mforall{}x,y:\mBbbR{}.    (x  =  y  \mLeftarrow{}{}\mRightarrow{}  \mforall{}m:\mBbbN{}\msupplus{}.  (|x  -  y|  \mleq{}  (r1/r(m))))



Date html generated: 2017_10_03-AM-09_06_12
Last ObjectModification: 2017_07_28-AM-07_41_59

Theory : reals


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