topological_add_group

A topological (additive) group is a group in which the addition and negation operations are continuous.

topological_group

A topological group is a group in which the multiplication and inversion operations are continuous.

add_group_with_zero_nhd

additive group with a neighbourhood around 0. Only used to construct a topology and uniform space.

This is currently only available for commutative groups, but it can be extended to non-commutative groups too.