Roles¶
Role¶
A role is what we call a position that an entity from an entity set fills in
- Two different roles need not be occupied by different entities. They may very well be filled in by the same entity
Example¶
Handing any weapon to any soldier is not a very smart idea. So, our civilisation needs to come up with an intelligent and hierarchical way to grant soldiers access to weaponry.
To have access to a gun, one must first be adept with the bow-and-arrow. To have access to a poleaxe, one must first be adept with the lance. The general wants us to generalise this concept to all weapons.
This leads us to a special kind of relation
- Weapon <- prerequisite of -> Weapon