UMLTP23 — At most one precondition

Why is it that there are definitional rules for limits number of preconditions to AT MOST one, couldn't there be more than one?

There are definitional rules limiting the number of test levels and test types of a test context to AT MOST one,  think of scenarios where a test context may cover more than one type and level (the XMI shows the upper limit value to be * therefore not enforcing this rule).

Weaken structural rules that only allow at most one relationship.

The restrictions applied by several structural rules are too narrow. The unnecessarily imply modeling restrictions which may reduce applicability of the specification in certain contexts.

This allows holds true for the structural rules that restrict the number of arbitration specifications to exactly one. With the arbitration specification binding mechanism introduced by UTP 2.2, these rules are outdated and shall be removed.