Nuprl Lemma : bag-summation-single-non-zero
∀[T,R:Type]. ∀[eq:EqDecider(T)]. ∀[add:R ⟶ R ⟶ R]. ∀[zero:R]. ∀[b:bag(T)]. ∀[f:T ⟶ R].
  ∀z:T. Σ(x∈b). f[x] = Σ(x∈[x∈b|eq x z]). f[x] ∈ R supposing ∀x:T. (x ↓∈ b 
⇒ ((x = z ∈ T) ∨ (f[x] = zero ∈ R))) 
  supposing IsMonoid(R;add;zero) ∧ Comm(R;add)
Proof
Definitions occuring in Statement : 
bag-member: x ↓∈ bs
, 
bag-summation: Σ(x∈b). f[x]
, 
bag-filter: [x∈b|p[x]]
, 
bag: bag(T)
, 
deq: EqDecider(T)
, 
comm: Comm(T;op)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
and: P ∧ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
, 
monoid_p: IsMonoid(T;op;id)
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
so_lambda: λ2x.t[x]
, 
deq: EqDecider(T)
, 
so_apply: x[s]
, 
cand: A c∧ B
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
, 
monoid_p: IsMonoid(T;op;id)
, 
uiff: uiff(P;Q)
, 
not: ¬A
, 
false: False
, 
eqof: eqof(d)
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
guard: {T}
, 
ident: Ident(T;op;id)
Lemmas referenced : 
bag-summation-split, 
equal_wf, 
infix_ap_wf, 
bag-summation_wf, 
assert_wf, 
bag-filter_wf, 
bag-member_wf, 
istype-universe, 
monoid_p_wf, 
comm_wf, 
bag_wf, 
deq_wf, 
bag-summation-is-zero, 
bnot_wf, 
bag-member-filter-set, 
eqof_wf, 
not_wf, 
istype-void, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_bnot, 
safe-assert-deq
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
promote_hyp, 
lambdaFormation_alt, 
productElimination, 
sqequalRule, 
lambdaEquality_alt, 
applyEquality, 
setElimination, 
rename, 
because_Cache, 
inhabitedIsType, 
independent_isectElimination, 
independent_pairFormation, 
equalitySymmetry, 
hyp_replacement, 
applyLambdaEquality, 
equalityTransitivity, 
setEquality, 
setIsType, 
universeIsType, 
functionIsType, 
unionIsType, 
equalityIsType1, 
dependent_functionElimination, 
isect_memberEquality_alt, 
axiomEquality, 
functionIsTypeImplies, 
productIsType, 
universeEquality, 
independent_functionElimination, 
unionElimination, 
voidElimination
Latex:
\mforall{}[T,R:Type].  \mforall{}[eq:EqDecider(T)].  \mforall{}[add:R  {}\mrightarrow{}  R  {}\mrightarrow{}  R].  \mforall{}[zero:R].  \mforall{}[b:bag(T)].  \mforall{}[f:T  {}\mrightarrow{}  R].
    \mforall{}z:T
        \mSigma{}(x\mmember{}b).  f[x]  =  \mSigma{}(x\mmember{}[x\mmember{}b|eq  x  z]).  f[x]  supposing  \mforall{}x:T.  (x  \mdownarrow{}\mmember{}  b  {}\mRightarrow{}  ((x  =  z)  \mvee{}  (f[x]  =  zero))) 
    supposing  IsMonoid(R;add;zero)  \mwedge{}  Comm(R;add)
Date html generated:
2019_10_15-AM-11_03_29
Last ObjectModification:
2018_10_09-PM-00_13_42
Theory : bags
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