Nuprl Lemma : absval_sum

∀[n:ℕ]. ∀[f:ℕn ⟶ ℤ].  (|Σ(f[x] | x < n)| ≤ Σ(|f[x]| | x < n))


Proof




Definitions occuring in Statement :  sum: Σ(f[x] | x < k),  absval: |i|,  int_seg: {i..j-},  nat: ℕ,  uall: ∀[x:A]. B[x],  so_apply: x[s],  le: A ≤ B,  function: x:A ⟶ B[x],  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  so_lambda: λ2x.t[x],  so_apply: x[s],  nat: ℕ,  subtype_rel: A ⊆r B,  all: ∀x:A. B[x],  implies: P ⇒ Q,  false: False,  ge: i ≥ j ,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  not: ¬A,  top: Top,  and: P ∧ Q,  prop: ℙ,  le: A ≤ B,  absval: |i|,  less_than': less_than'(a;b),  guard: {T},  int_seg: {i..j-},  lelt: i ≤ j < k,  decidable: Dec(P),  or: P ∨ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  ifthenelse: if b then t else f fi ,  bfalse: ff,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  le_weakening,  int-triangle-inequality,  le_functionality,  int_term_value_add_lemma,  itermAdd_wf,  lelt_wf,  decidable__lt,  sum_wf,  assert_of_bnot,  eqff_to_assert,  iff_weakening_uiff,  not_wf,  bnot_wf,  bfalse_wf,  iff_transitivity,  assert_of_eq_int,  eqtt_to_assert,  assert_wf,  btrue_wf,  equal_wf,  uiff_transitivity,  bool_wf,  eq_int_wf,  primrec-unroll,  subtype_rel_self,  int_seg_subtype,  subtype_rel_dep_function,  int_term_value_subtract_lemma,  int_formula_prop_not_lemma,  itermSubtract_wf,  intformnot_wf,  subtract_wf,  decidable__le,  int_seg_properties,  le_wf,  false_wf,  primrec0_lemma,  nat_wf,  primrec_wf,  less_than'_wf,  less_than_wf,  ge_wf,  int_formula_prop_wf,  int_formula_prop_less_lemma,  int_term_value_var_lemma,  int_term_value_constant_lemma,  int_formula_prop_le_lemma,  int_formula_prop_and_lemma,  intformless_wf,  itermVar_wf,  itermConstant_wf,  intformle_wf,  intformand_wf,  satisfiable-full-omega-tt,  nat_properties,  absval_wf,  int_seg_wf,  sum-as-primrec
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  lemma_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  lambdaEquality,  applyEquality,  natural_numberEquality,  setElimination,  rename,  hypothesis,  because_Cache,  lambdaFormation,  intWeakElimination,  independent_isectElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  dependent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  independent_functionElimination,  productElimination,  independent_pairEquality,  addEquality,  axiomEquality,  equalityTransitivity,  equalitySymmetry,  functionEquality,  minusEquality,  dependent_set_memberEquality,  setEquality,  unionElimination,  equalityElimination,  impliesFunctionality,  equalityEquality

Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[f:\mBbbN{}n  {}\mrightarrow{}  \mBbbZ{}].    (|\mSigma{}(f[x]  |  x  <  n)|  \mleq{}  \mSigma{}(|f[x]|  |  x  <  n))



Date html generated: 2016_05_14-PM-04_27_53
Last ObjectModification: 2016_01_14-PM-11_34_45

Theory : num_thy_1


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