We show that the fixed-point
subnet of a strongly additive conformal net under the action of a compact group is
strongly additive. Using the idea of the proof we define the notion of strong
additivity for a pair of conformal nets and we show that a key fact about induction of
pairs, proved earlier under the assumption of finite index, can be generalized to
strongly additive pairs of conformal nets. These results are used to classify conformal
nets of central charge c = 1 that are not necessarily rational and satisfy a spectrum
condition.