Table 3. OCL rules for the model validation process II.

Rule 7	SLA_compensation_must_be_greater_than_or_equal_to_zero
Rule Description	The compensation cost for high-priority users must be greater or equal to zero.
Rule OCL Code	context SLA inv self.vmcost ->forAll(vmcost | vmcost.compensation >= 0)
Notification Type	Error
MSCC Recommendation	Please, enter a positive value for the compensation cost value!
Rule 8	CloudProvider_offer_must_be_greater_than_or_equal_to_zero
Rule OCL Code	context CloudProvider inv self.offer >= 0
Notification Type	Error
MSCC Recommendation	Please, enter a positive value for the offer cost value!