Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:In recent years there has been a lot of interest in the definition of so-called weakly-relational numeric domains, whose complexity and precision are in between the (non-relational) abstract domain of intervals [9] and the (relational) abstract domain of convex polyhedra [10].
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