[2] Length is a pre-defined function on the path operator providing the length (i.e., the number of edges) of a path.

[3] To simplify the presentation, we do not take into account here the constraint due to the Group by clause.

[4] Length is a pre-defined function on the geometric operator providing the geometric length.

[5] Due to space limitation, the step by step presentation of each query is not possible, therefore we present the final step of the query definition process (just after the query-area validation).

^* Cigales stands for: Cartographical Interface Generating an Adapted Language for Extensible Systems