Nuprl Lemma : exists-rneq-iff

∀n:ℕ. ∀a,b:ℕn ⟶ ℝ.  (∃i:ℕn. a[i] ≠ b[i] ⇐⇒ r0 < Σ{|a[i] - b[i]| | 0≤i≤n - 1})


Proof




Definitions occuring in Statement :  rsum: Σ{x[k] | n≤k≤m},  rneq: x ≠ y,  rless: x < y,  rabs: |x|,  rsub: x - y,  int-to-real: r(n),  real: ℝ,  int_seg: {i..j-},  nat: ℕ,  so_apply: x[s],  all: ∀x:A. B[x],  exists: ∃x:A. B[x],  iff: P ⇐⇒ Q,  function: x:A ⟶ B[x],  subtract: n - m,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  uall: ∀[x:A]. B[x],  member: t ∈ T,  nat: ℕ,  iff: P ⇐⇒ Q,  and: P ∧ Q,  so_lambda: λ2x.t[x],  so_apply: x[s],  int_seg: {i..j-},  lelt: i ≤ j < k,  ge: i ≥ j ,  exists: ∃x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  not: ¬A,  implies: P ⇒ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  false: False,  top: Top,  prop: ℙ,  le: A ≤ B,  less_than: a < b,  rev_implies: P ⇐ Q,  rless: x < y,  sq_exists: ∃x:{A| B[x]},  nat_plus: ℕ+
Lemmas referenced :  subtract-add-cancel,  rsum-of-nonneg-positive-iff,  subtract_wf,  rabs_wf,  rsub_wf,  int_seg_wf,  nat_properties,  decidable__lt,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformless_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  lelt_wf,  zero-rleq-rabs,  nat_plus_properties,  rless_wf,  int-to-real_wf,  rsum_wf,  iff_wf,  exists_wf,  rneq_wf,  real_wf,  nat_wf,  rneq-iff-rabs,  rneq-if-rabs
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setElimination,  rename,  hypothesisEquality,  hypothesis,  natural_numberEquality,  addLevel,  productElimination,  independent_pairFormation,  impliesFunctionality,  dependent_functionElimination,  because_Cache,  sqequalRule,  lambdaEquality,  applyEquality,  functionExtensionality,  dependent_set_memberEquality,  unionElimination,  independent_isectElimination,  approximateComputation,  independent_functionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  addEquality,  functionEquality

Latex:
\mforall{}n:\mBbbN{}.  \mforall{}a,b:\mBbbN{}n  {}\mrightarrow{}  \mBbbR{}.    (\mexists{}i:\mBbbN{}n.  a[i]  \mneq{}  b[i]  \mLeftarrow{}{}\mRightarrow{}  r0  <  \mSigma{}\{|a[i]  -  b[i]|  |  0\mleq{}i\mleq{}n  -  1\})



Date html generated: 2017_10_03-AM-09_00_31
Last ObjectModification: 2017_06_16-AM-11_47_25

Theory : reals


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