Nuprl Lemma : rneq-iff-rabs

∀x,y:ℝ.  (x ≠ y ⇐⇒ r0 < |x - y|)


Proof




Definitions occuring in Statement :  rneq: x ≠ y,  rless: x < y,  rabs: |x|,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  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,  top: Top,  rneq: x ≠ y,  or: P ∨ Q,  guard: {T},  uimplies: b supposing a,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  uiff: uiff(P;Q)
Lemmas referenced :  rneq_wf,  rless_wf,  int-to-real_wf,  rabs_wf,  rsub_wf,  real_wf,  rabs-as-rmax,  rmax_strict_ub,  rminus_wf,  rless-implies-rless,  real_term_polynomial,  itermSubtract_wf,  itermVar_wf,  itermMinus_wf,  itermConstant_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_var_lemma,  real_term_value_minus_lemma,  req-iff-rsub-is-0,  rneq-if-rabs
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  independent_pairFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  natural_numberEquality,  sqequalRule,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_functionElimination,  productElimination,  independent_functionElimination,  unionElimination,  inrFormation,  independent_isectElimination,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  inlFormation,  because_Cache

Latex:
\mforall{}x,y:\mBbbR{}.    (x  \mneq{}  y  \mLeftarrow{}{}\mRightarrow{}  r0  <  |x  -  y|)



Date html generated: 2017_10_03-AM-08_31_12
Last ObjectModification: 2017_07_28-AM-07_26_59

Theory : reals


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