A requirement that two activities or features keep a minimum separation distance, aminimum elapsed time between them, or both together as a conditional rule:"installations within 3 m of each other must be at least 24 h apart". It is genericacross domains: adjacent columns protecting fresh grout from vibration,grout-injection stages avoiding hydraulic fracture of a neighbor still curing, a newborehole standing off from a utility, a pile sequenced away from a monitoredstructure. It states a relation between two features, or two members of apopulation, over a length and a duration, which the single operator and limit of acriterion cannot combine; it therefore substitutesdiggs:AbstractProgramSpecification directly. appliesToFeatureType (inherited) namesthe population the constraint governs, the subject; referenceFeatureType names whatthe subject must keep clear of. If referenceFeatureType is absent, every member ofthe subject population clears every other member. If it names a different type, theconstraint relates the subject population to that other one, typically apre-existing feature the program did not install and cannot date, in which caseminimumElapsedTime does not apply on that side. minimumSeparation andminimumElapsedTime are independently optional. Both present is the conditional case:within minimumSeparation, the two governing timestamps must be at leastminimumElapsedTime apart. minimumSeparation alone is an unconditional exclusionzone. minimumElapsedTime alone is an unconditional sequencing gap for every pair thescope selects. At least one of the two is expected; the validation chain checks it.The object records the rule, not the check: evaluating it means finding, for everypair of features the scope selects, the separation between their locations (perseparationBasis) and the elapsed time between their governing timestamps (perelapsedTimeBasis, typically each feature's installingdiggs:AbstractConstructionActivity/activityDateTime), and comparing each against itsthreshold.
Database handle for the object. It is of XML type ID, so is constrained to beunique in the XML document within which it occurs. An external identifier for the object inthe form of a URI may be constructed using standard XML and XPointer methods. This is doneby concatenating the URI for the document, a fragment separator, and the value of the idattribute.
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<element name="ClearanceConstraint" type="diggs:ClearanceConstraintType" substitutionGroup="diggs:AbstractProgramSpecification"><annotation><documentation>A requirement that two activities or features keep a minimum separation distance, a minimum elapsed time between them, or both together as a conditional rule: "installations within 3 m of each other must be at least 24 h apart". It is generic across domains: adjacent columns protecting fresh grout from vibration, grout-injection stages avoiding hydraulic fracture of a neighbor still curing, a new borehole standing off from a utility, a pile sequenced away from a monitored structure. It states a relation between two features, or two members of a population, over a length and a duration, which the single operator and limit of a criterion cannot combine; it therefore substitutes diggs:AbstractProgramSpecification directly. appliesToFeatureType (inherited) names the population the constraint governs, the subject; referenceFeatureType names what the subject must keep clear of. If referenceFeatureType is absent, every member of the subject population clears every other member. If it names a different type, the constraint relates the subject population to that other one, typically a pre-existing feature the program did not install and cannot date, in which case minimumElapsedTime does not apply on that side. minimumSeparation and minimumElapsedTime are independently optional. Both present is the conditional case: within minimumSeparation, the two governing timestamps must be at least minimumElapsedTime apart. minimumSeparation alone is an unconditional exclusion zone. minimumElapsedTime alone is an unconditional sequencing gap for every pair the scope selects. At least one of the two is expected; the validation chain checks it. The object records the rule, not the check: evaluating it means finding, for every pair of features the scope selects, the separation between their locations (per separationBasis) and the elapsed time between their governing timestamps (per elapsedTimeBasis, typically each feature's installing diggs:AbstractConstructionActivity/activityDateTime), and comparing each against its threshold.</documentation></annotation></element>
