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: 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
, 
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: P 
⇒ Q
, 
false: False
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
subtype_rel: A ⊆r B
, 
real: ℝ
, 
prop: ℙ
, 
uimplies: b supposing a
, 
int_seg: {i..j-}
, 
lelt: i ≤ j < k
, 
callbyvalueall: callbyvalueall, 
has-value: (a)↓
, 
has-valueall: has-valueall(a)
, 
top: Top
, 
compose: f o 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
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