Under some conditions the Folding Generator produces unknown sorts in the -Folding.generated.esv. After a lot of reductions I could isolate a trivial small grammar to demonstrate the error - see the attachment. In my project I could (until now) eliminate this error by things like:

A B C? -> X {cons(“X”)}

replaced by:

A B -> X {cons(“Xe”)}

A B C -> X {cons(“X”)}

Submitted by Otto Hausbacher on 21 August 2010 at 10:06

This problem also occurs with Plus lists. A rule "test" "cases" "are" {TestSuite ","}+ "." -> Automation {bracket} causes to generate an entry ListPlusOfTestSuite0.