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Constraint (from Kernel ) on page 57

Issue 8509 -capitalize ‘boolean’

An InteractionConstraint is a Boolean expression that guards an operand in a CombinedFragment . InteractionConstraint is a
specialization of Constraint.

Furthermore the InteractionConstraint contains two expressions designating the minimum and maximum number of times a loop
CombinedFragment should execute.

Associations

• minint: ValueSpecification [0..1] The minimum number of iterations of a loop.

• maxint: ValueSpecification [0..1] The maximum number of iterations of a loop.

Constraints

[1] The dynamic variables that take part in the constraint must be owned by the ConnectableElement corresponding to the covered
Lifeline .

[2] The constraint may contain references to global data or write-once data.

[3] Minint/maxint can only be present if the InteractionConstraint is associated with the operand of a loop CombinedFragment .

[4] If minint is specified, then the expression must evaluate to a non-negative integer.

[5] If maxint is specified, then the expression must evaluate to a positive integer.

[6] If maxint is specified, then minint must be specified and the evaluation of maxint must be >= the evaluation of minint.

Semantics

InteractionConstraint s are always used in
connection with CombinedFragment s, see CombinedFragment (from
Fragments ) on page 487.

Notation

An InteractionConstraint is shown in square brackets covering the lifeline where the first event occurrence will occur, positioned
above that event, in the containing Interaction or InteractionOperand .

<interactionconstraint> ::= [‘[‘ (<Boolean-expression’ | ‘else‘) ‘]’]

When the InteractionConstraint is omitted, true is assumed.

Issue 7988 -Add second figure to reference.

Please refer to an example of InteractionConstraint s
in Figure 14.11 on page 492 and Figure 14.28 on page 539.