If one object is similar to another, it shares all the components and attributes of the other object. No error is generated if the similar object has a dissimilar attribute – it is ignored.
Object1 and Object2 are similar.
The bridge will be used both ways if they are both in a subject ObjectGroup. Here, similarity between objects includes similarity between relations. This allows us to share properties among actions and states.
A and B are similar in shape.
If an object is similar in shape to another object, then it shares only the attribute of shape. We can specify size, weight, appearance – any attribute it might have.
The bridge will be used both ways if the target attributes are both in a subject ObjectGroup.
Object1 is similar to Object2.
The bridge will not be used if the similar object (Object1) has an attribute the original (Object2) does not have.
This is another way of controlling inheritance – all the properties are inherited except the ones we nominate as different, or which clash with the object’s own inheritance.
We have to handle "not similar" and "dissimilar" – we should assume the attributes are different, and "not dissimilar", which brings us back to similar.