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≤1})


Proof




Definitions occuring in Statement :  rsum: Σ{x[k] n≤k≤m} rneq: x ≠ y rless: x < y rabs: |x| rsub: y int-to-real: r(n) real: int_seg: {i..j-} nat: so_apply: x[s] all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q function: x:A ⟶ B[x] subtract: m natural_number: $n
Definitions unfolded in proof :  all: x:A. B[x] uall: [x:A]. B[x] member: t ∈ T nat: iff: ⇐⇒ Q and: P ∧ Q so_lambda: λ2x.t[x] so_apply: x[s] int_seg: {i..j-} lelt: i ≤ j < k ge: i ≥  exists: x:A. B[x] decidable: Dec(P) or: P ∨ Q uimplies: supposing a not: ¬A implies:  Q satisfiable_int_formula: satisfiable_int_formula(fmla) false: False top: Top prop: le: A ≤ B less_than: a < b rev_implies:  Q rless: x < y sq_exists: x:{A| B[x]} nat_plus: +
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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