Definition 4.3 (Case, trace, event log) Let C be the case universe, i.e., the set of all possible case identifiers. Cases, like events, have attributes. For any case c ∈ C and name n ∈ AN: #n(c) is the value of attribute n for case c (#n(c) = ⊥ if case c has no attribute named n). Each case has a special mandatory attribute trace: # trace(c) ∈ E∗.1 cˆ = #trace(c) is a shorthand for referring to the trace of a case.