Aggregation, Association and Composition

[AndreasRausch]

https://leanpub.com/isaqbglossary/read#Aggregation
https://leanpub.com/isaqbglossary/read#Association
https://leanpub.com/isaqbglossary/read#Composition

I'm totally struggeling with these definitions.

The UML has a defined three types of Asscociations between classes, that might be used in class diagramms: Association, Aggregation and Composition.

However, these definitions, concepts and terms are not clearly defined in OOP like mentioned in the Golssary.

Moreover, even worse: There is a general concept of Composition, well known in Math. It means:
If you have an Element x and y, both of type A and you've got an composition operator op, you are able to create a new element z of type A by composing the to elements y and y.
z := x op y!

OOP and UML Classes and so on, suffer from the non existence of an composition operator! That's the reason my we use Components for Architecture and not Classes oder Objects!!

[gernotstarke]

what change do you suggest?