POSC Specifications: Epicentre Version 3.0
Logical Data Model
ENTITY
EARTH_FEATURE_CLASSIFICATION
SUBTYPE OF
(
transient_association
);
earth_feature :
earth_feature
;
earth_feature_class :
OPTIONAL
earth_feature_class
;
material_class :
OPTIONAL
material_class
;
UNIQUE
si:
transient_association
.end_time,
transient_association
.start_time, earth_feature_class, earth_feature, material_class;
WHERE
mse: EXISTS(earth_feature_class) XOR EXISTS(material_class);
END_ENTITY
; (* earth_feature_classification *)
Generated on Tue Jul 10 19:37:46 2001
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