Nuprl Lemma : infinitesmal-difference

∀[x,y:ℝ].  uiff(x = y;∀[k:ℕ+]. (|x - y| ≤ (r1/r(k))))


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+,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  natural_number: $n
Definitions unfolded in proof :  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  member: t ∈ T,  rev_implies: P ⇐ Q,  uall: ∀[x:A]. B[x],  so_lambda: λ2x.t[x],  nat_plus: ℕ+,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  implies: P ⇒ Q,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  prop: ℙ,  so_apply: x[s],  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B,  subtype_rel: A ⊆r B,  itermConstant: "const",  req_int_terms: t1 ≡ t2
Lemmas referenced :  iff_weakening_uiff,  uall_wf,  nat_plus_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,  req_wf,  infinitesmal-zero,  less_than'_wf,  req_witness,  uiff_wf,  real_wf,  req-implies-req,  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
Rules used in proof :  cut,  addLevel,  sqequalHypSubstitution,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  productElimination,  thin,  independent_pairFormation,  isect_memberFormation,  introduction,  independent_isectElimination,  hypothesis,  extract_by_obid,  isectElimination,  sqequalRule,  lambdaEquality,  hypothesisEquality,  natural_numberEquality,  setElimination,  rename,  because_Cache,  inrFormation,  dependent_functionElimination,  independent_functionElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  computeAll,  independent_pairEquality,  applyEquality,  minusEquality,  cumulativity,  universeEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}[x,y:\mBbbR{}].    uiff(x  =  y;\mforall{}[k:\mBbbN{}\msupplus{}].  (|x  -  y|  \mleq{}  (r1/r(k))))



Date html generated: 2017_10_03-AM-08_52_14
Last ObjectModification: 2017_07_28-AM-07_35_04

Theory : reals


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