Safe aspect composition

Introduction When different aspects [4] are composed, one must ensure that the resulting composition does not cause conflicts. This problem appeared to be central to the work of the authors. The corresponding discussions that took place during the workshop led to a categorization of conflicts relating to the composition of aspects. We thus present three general classes of conflicts associated with aspect composition, and consider possible remedies. The first kind of conflicts, discussed in Sec. 2, is inherent, i.e., it is the kind of conflicts where a given combination of aspects should be rejected by the translation system. Section 3 deals with the situation where certain aspects should be combined but cannot---because of accidentally conflicting characteristics of the implementation. Finally, as described in Sec.4, aspect combinations may give rise to spurious conflicts, where the combination is intended to work---and it would