Nuprl Lemma : rabs-rsum

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


Proof




Definitions occuring in Statement :  rsum: Σ{x[k] n≤k≤m} rleq: x ≤ y rabs: |x| real: int_seg: {i..j-} uall: [x:A]. B[x] so_apply: x[s] function: x:A ⟶ B[x] add: m natural_number: $n int:
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T rsum: Σ{x[k] n≤k≤m} rleq: x ≤ y rnonneg: rnonneg(x) all: x:A. B[x] le: A ≤ B and: P ∧ Q not: ¬A implies:  Q false: False so_lambda: λ2x.t[x] so_apply: x[s] subtype_rel: A ⊆B real: prop: uimplies: supposing a int_seg: {i..j-} lelt: i ≤ j < k callbyvalueall: callbyvalueall has-value: (a)↓ has-valueall: has-valueall(a) top: Top compose: g rev_uimplies: rev_uimplies(P;Q) rge: x ≥ y guard: {T}
Lemmas referenced :  less_than'_wf rsub_wf rsum_wf rabs_wf int_seg_wf real_wf nat_plus_wf value-type-has-value int-value-type valueall-type-has-valueall list_wf list-valueall-type real-valueall-type map_wf le_wf less_than_wf from-upto_wf evalall-reduce valueall-type-real-list radd-list_wf-bag list-subtype-bag map-map subtype_rel_self equal_wf rleq_weakening_equal rleq_functionality_wrt_implies radd-list-rabs
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut sqequalRule sqequalHypSubstitution lambdaEquality dependent_functionElimination thin hypothesisEquality productElimination independent_pairEquality because_Cache extract_by_obid isectElimination applyEquality functionExtensionality addEquality natural_numberEquality hypothesis setElimination rename minusEquality axiomEquality equalityTransitivity equalitySymmetry functionEquality isect_memberEquality intEquality voidElimination independent_isectElimination setEquality productEquality lambdaFormation dependent_set_memberEquality callbyvalueReduce voidEquality independent_functionElimination

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



Date html generated: 2017_10_03-AM-09_00_02
Last ObjectModification: 2017_07_28-AM-07_39_21

Theory : reals


Home Index