MSC: Error parsing nested sequence

out telecommand({ tc automode: { level e1 } }) to agnet;

This causes a parsing error which I don't understand. The error is due to the brackets around level e1. But this is a standard SEQUENCE representation. In MSC,g4 I think this is wrong:

asnChoice should be name COLON (asn1Item | asnValue)" and I think this would cover choiceOfChoice that would not be needed anymore.