Reading about narremes88 suggested us to elaborate on a basic software trace (log) unit. One candidate is a trace message invariant, a skeleton trace message similar to a format string. There is also a corresponding software trace analysis pattern called Message Invariant (Volume 6, page 251). Although this might be too an elementary unit akin to a sentence level and another possible candidate is a macromessage, a combination of several messages serving some semantic function. There is a corresponding general pattern Macrofunction (page 279) and an example of a concrete analysis pattern called Exception Stack Trace (Volume 4, page 337). The actual software narreme might be situated between these two extremes: invariants and macrofunctions.
If you are new to a software narratology field please look at these articles placed in chronological order (except a pattern catalog):
• Software Narratology: A Definition (Volume 3, page 342)
• Basic Software PLOTs (Volume 5, page 272)
• Two Readings of a Software Trace (Volume 5, page 274)
• The Extended Software Trace (Volume 5, page 277)
• Presenting a Software Story (Volume 5, page 278)
• Close and Deconstructive Readings of a Software Trace (Volume 6, page 240)
• Software Trace Analysis Pattern Catalog89
88 http://en.wikipedia.org/wiki/Narreme
89 http://www.dumpanalysis.org/blog/index.php/trace-analysis-patterns/