- Construcció del frame a partir de una definició
- centerOfGravity<n>(X) = div( sum( mult(index(X),pow<n>(X))), sum(pow<n>(X)) )
- SV summatory(X) = accomulate(sum,X)
- VV powered<n>(X) = vectorize(pow<b>,X)
- ponderedSum(X) = accomulate(sum, productindex(I),I))


+ Getting the attribute index
	+ When empty
	+ When added
	+ When two added
	+ When wrong name
+ Place data inside the Scope
+ Split definition and data
	+ remove Pool::GetIndex
	+ remove Pool::Add
	+ posar el atributo spec com a const
+ duplicated attribute names
+ Separate Pool and PoolSpec tests in two fixtures
+ Move attribute pool allocation and deallocation to the spec
* Introduce multiple types
	+ Multitype Spec::Add
	+ Multitype Pool::Get
	+ Spec::AssertType
	+ Pool::Get check for type
- Select the scope specification by name
	- ScopeSpecFactory
- Consider using a iterator/vector interface
- Multilevel pools
- XML for the Pool
- XML for the Pool Spec
- Multitype XML loading