Figure 1.

S3QL language specification using rail diagrams. Rail diagrams are read from the left to the right - any string that can be composed following these diagrams is a valid S3QL query. Valid forms of E and E.a will vary according to the Core Model used in the KOS. For example, if the S3DB Core model is used, any entity in figure 2 can be used in place of E; upon choice of E, E.a is any attribute that can be attained by following a line from E.