Establish pattern for a material being composed of many pieces of a feature

[GoogleCodeExporter]

Consider, for example, gravel: 'environmental material' and 
primarily_composed_of some 'piece of gravel'

This should suggest that gravel (the material) is composed of multiple "pieces" 
of gravel (which is defined elsewhere). 

Perhaps using some sort of "aggregate of pieces of gravel" may work.

Original issue reported on code.google.com by p.buttig...@gmail.com on 5 Oct 2014 at 2:26

[GoogleCodeExporter]

Not following - so "aggregate of pieces of gravel" would be the same as the 
current 'gravel'?

Original comment by cmung...@gmail.com on 5 Oct 2014 at 9:22

• Added labels: ****
• Removed labels: ****

[pbuttigieg]

The original post was odd, sorry.
We currently have:
gravel = 'environmental material' and ('composed primarily of' some 'piece of gravel')
This seems to suggest that one piece of grave is the primary constituent of a portion of gravel. If this is the case, we would need something more like:
gravel = 'environmental material' and ('composed primarily of' some 'aggregate of pieces of gravel')

In the environmental material sense, 'a portion of gravel' includes stuff other than the gravel itself (e.g. dust in the interstices).

I could add the 'aggregate of X' classes, but these should be under BFO:'object aggregate'. To avoid double inheritance, we should attempt to resolve the relationship between 'environmental feature' and its subclasses: this should be more 'role-like' (i.e. any material entity can act as an environmental feature if it determines and environmental system).