Explore a 22-minute conference talk from Erlang 2023 introducing a small step semantics for a subset of Core Erlang that models its monitoring and signal systems. Delve into the presentation by Aurélie Kong Win Chang, Jérôme Feret, and Gregor Gössler as they discuss their approach to enabling the construction of causal explanations for property violations in Erlang programs. Examine the impact of message order on faulty behavior and gain insights into the design choices made in developing this semantics. Understand how this work contributes to a broader project on causal debugging of concurrent programs in Erlang, setting the stage for future research in this area.