I´ve tried this, but i get an error while generating the Xtext Artifacts.
warning(200): ../christ.xtext.statemachinediagram.sdsl/src-gen/christ/xtext/statemachinediagram/sdsl/parser/antlr/internal/InternalSDsl.g:3639:1: Decision can match input such as "'.' RULE_ID" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
Semantic predicates were present but were hidden by actions.