Nuprl Lemma : rsum-triangle-inequality2

∀[n,m:ℤ]. ∀[x,y:{n..m + 1-} ⟶ ℝ].  ((Σ{|y[i]| | n≤i≤m} - Σ{|x[i]| | n≤i≤m}) ≤ Σ{|x[i] + y[i]| | n≤i≤m})


Proof




Definitions occuring in Statement :  rsum: Σ{x[k] | n≤k≤m},  rleq: x ≤ y,  rabs: |x|,  rsub: x - y,  radd: a + b,  real: ℝ,  int_seg: {i..j-},  uall: ∀[x:A]. B[x],  so_apply: x[s],  function: x:A ⟶ B[x],  add: n + m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  rleq: x ≤ y,  rnonneg: rnonneg(x),  all: ∀x:A. B[x],  le: A ≤ B,  and: P ∧ Q,  not: ¬A,  implies: P ⇒ Q,  false: False,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  prop: ℙ,  int_seg: {i..j-},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  rev_uimplies: rev_uimplies(P;Q),  rge: x ≥ y,  guard: {T},  uiff: uiff(P;Q)
Lemmas referenced :  req_weakening,  radd_comm,  rabs_functionality,  rsum_functionality2,  rleq_functionality,  rsum-triangle-inequality1,  rleq_functionality_wrt_implies,  rleq_weakening_equal,  le_wf,  lelt_wf,  int_formula_prop_wf,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_not_lemma,  int_formula_prop_and_lemma,  intformle_wf,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  intformless_wf,  intformnot_wf,  intformand_wf,  satisfiable-full-omega-tt,  decidable__lt,  real_wf,  nat_plus_wf,  int_seg_wf,  radd_wf,  rabs_wf,  rsum_wf,  rsub_wf,  less_than'_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  sqequalHypSubstitution,  lambdaEquality,  dependent_functionElimination,  thin,  hypothesisEquality,  productElimination,  independent_pairEquality,  because_Cache,  lemma_by_obid,  isectElimination,  applyEquality,  hypothesis,  addEquality,  natural_numberEquality,  minusEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  functionEquality,  isect_memberEquality,  intEquality,  voidElimination,  dependent_set_memberEquality,  independent_pairFormation,  unionElimination,  independent_isectElimination,  dependent_pairFormation,  int_eqEquality,  voidEquality,  computeAll,  lambdaFormation

Latex:
\mforall{}[n,m:\mBbbZ{}].  \mforall{}[x,y:\{n..m  +  1\msupminus{}\}  {}\mrightarrow{}  \mBbbR{}].
    ((\mSigma{}\{|y[i]|  |  n\mleq{}i\mleq{}m\}  -  \mSigma{}\{|x[i]|  |  n\mleq{}i\mleq{}m\})  \mleq{}  \mSigma{}\{|x[i]  +  y[i]|  |  n\mleq{}i\mleq{}m\})



Date html generated: 2016_05_18-AM-07_48_30
Last ObjectModification: 2016_01_17-AM-02_08_57

Theory : reals


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