Nuprl Lemma : bag-summation-single
∀[R:Type]. ∀[add:R ⟶ R ⟶ R]. ∀[zero:R].
  ∀[T:Type]. ∀[f:T ⟶ R]. ∀[a:T].  (Σ(x∈{a}). f[x] = f[a] ∈ R) supposing IsMonoid(R;add;zero) ∧ Comm(R;add)
Proof
Definitions occuring in Statement : 
bag-summation: Σ(x∈b). f[x]
, 
single-bag: {x}
, 
comm: Comm(T;op)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
and: P ∧ Q
, 
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
, 
top: Top
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
and: P ∧ Q
, 
monoid_p: IsMonoid(T;op;id)
, 
assoc: Assoc(T;op)
, 
ident: Ident(T;op;id)
, 
infix_ap: x f y
, 
prop: ℙ
Lemmas referenced : 
bag-summation-single-sq, 
istype-void, 
monoid_p_wf, 
comm_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalRule, 
sqequalReflexivity, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
sqequalTransitivity, 
computationStep, 
isectElimination, 
thin, 
isect_memberEquality_alt, 
voidElimination, 
hypothesis, 
isect_memberFormation_alt, 
productElimination, 
applyEquality, 
hypothesisEquality, 
universeIsType, 
axiomEquality, 
isectIsTypeImplies, 
inhabitedIsType, 
functionIsType, 
productIsType, 
because_Cache, 
instantiate, 
universeEquality
Latex:
\mforall{}[R:Type].  \mforall{}[add:R  {}\mrightarrow{}  R  {}\mrightarrow{}  R].  \mforall{}[zero:R].
    \mforall{}[T:Type].  \mforall{}[f:T  {}\mrightarrow{}  R].  \mforall{}[a:T].    (\mSigma{}(x\mmember{}\{a\}).  f[x]  =  f[a]) 
    supposing  IsMonoid(R;add;zero)  \mwedge{}  Comm(R;add)
Date html generated:
2019_10_15-AM-11_00_42
Last ObjectModification:
2019_08_13-PM-00_01_48
Theory : bags
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