Nuprl Lemma : bag-summation-reindex
∀[R:Type]. ∀[add:R ⟶ R ⟶ R]. ∀[zero:R].
  ∀[T,A:Type]. ∀[g:T ⟶ A]. ∀[h:A ⟶ T]. ∀[f:T ⟶ R].
    ∀[b:bag(T)]. (Σ(x∈b). f[x] = Σ(x∈bag-map(g;b)). f[h x] ∈ R) supposing ∀x:T. (x = (h (g x)) ∈ T) 
  supposing Comm(R;add) ∧ Assoc(R;add)
Proof
Definitions occuring in Statement : 
bag-summation: Σ(x∈b). f[x]
, 
bag-map: bag-map(f;bs)
, 
bag: bag(T)
, 
comm: Comm(T;op)
, 
assoc: Assoc(T;op)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
and: P ∧ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
top: Top
, 
and: P ∧ Q
, 
subtype_rel: A ⊆r B
, 
all: ∀x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
squash: ↓T
, 
uimplies: b supposing a
, 
cand: A c∧ B
, 
prop: ℙ
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
Lemmas referenced : 
bag-summation-map, 
bag-subtype-list, 
bag-summation_wf, 
equal_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
bag_wf, 
all_wf, 
comm_wf, 
assoc_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
sqequalTransitivity, 
computationStep, 
isectElimination, 
thin, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
hypothesisEquality, 
applyEquality, 
dependent_functionElimination, 
hypothesis, 
lambdaEquality, 
imageElimination, 
because_Cache, 
independent_isectElimination, 
independent_pairFormation, 
equalityTransitivity, 
equalitySymmetry, 
functionExtensionality, 
cumulativity, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_functionElimination, 
functionEquality, 
productEquality, 
isect_memberFormation, 
axiomEquality
Latex:
\mforall{}[R:Type].  \mforall{}[add:R  {}\mrightarrow{}  R  {}\mrightarrow{}  R].  \mforall{}[zero:R].
    \mforall{}[T,A:Type].  \mforall{}[g:T  {}\mrightarrow{}  A].  \mforall{}[h:A  {}\mrightarrow{}  T].  \mforall{}[f:T  {}\mrightarrow{}  R].
        \mforall{}[b:bag(T)].  (\mSigma{}(x\mmember{}b).  f[x]  =  \mSigma{}(x\mmember{}bag-map(g;b)).  f[h  x])  supposing  \mforall{}x:T.  (x  =  (h  (g  x))) 
    supposing  Comm(R;add)  \mwedge{}  Assoc(R;add)
Date html generated:
2017_10_01-AM-08_51_12
Last ObjectModification:
2017_07_26-PM-04_33_10
Theory : bags
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