  Interaction models describe the exchange of messages between the different
components of distributed systems. We have previously defined a small-step
operational semantics for interaction models. The paper extends this work by
presenting an approach for checking the validity of multi-traces against
interaction models. A multi-trace is a collection of traces (sequences of
emissions and receptions), each representing a local view of the same global
execution of the distributed system. We have formally proven our approach,
studied its complexity, and implemented it in a prototype tool. Finally, we
discuss some observability issues when testing distributed systems via the
analysis of multi-traces.
