Complex sentence: And thirly, series can be synonymous with "sequence"; according to Cauchy restricted to: infinite sequences with terms for which distance and addition is defined (allowing to study clustering of its terms and its partial sums).
Split into simpler sentences: And thirly, series can be synonymous with "sequence". According to Cauchy restricted to: infinite sequences with terms for which distance and addition is defined (allowing to study clustering of its terms and its partial sums).