UML14 — UML 1.4 RTF Issue: changeability in associations

Changeability in associations

Changeability as currently described does not make sense when applied to
associations. It is summarized as:

[p 2-21] When placed on a target end, specifies whether an instance of
the Association may be modified from the source end. Possibilities
are:

What does "modified from the source end" mean?

[p 2-21] frozen - No links may be added after the creation of the
source object.

[p 2-57] the link cannot be modified once it has been initialized
(frozen).

No links may be added to what? The source/target objects, the link
itself? See below for the conflicting answers:

[p 2-21] addOnly - Links may be added at any time from the source
object, but once created a link may not be removed from the
source end.

[p 2-57] new links of the association may be added but not removed or
altered (addOnly)

Again, what does it mean to modify an association from "an end"? It
doesn't mean the objects at the ends, according to this:

These constraints do not affect the modifiability of the objects
themselves that are attached to the links. Moreover, t ) the
classifier, or (a child of) the classifier itself.

(The second sentence has too many typos to understand).

Finally, compare the above to:

An association-end also specifies whether or not an instance playing
that role in a connection may be replaced by another instance. It may
state that no constraints exist (changeable), that the link cannot be
modified once it has been initialized (frozen), or that new links of
the association may be added but not removed or altered (addOnly).

The first sentence implies the link is what is frozen, but that isn't
consistent with the last sentence.

No Data Available