Een beetje rare foutmelding van sdf2rtg:

[ core-sdf-grammar2rtg | error ] No constructor name specified in production:
[ core-sdf-grammar2rtg | error ] "else" -> <"let"|"in"|"end"|"while"|"do"|"function"|"if"|"then"|"else"-CF>
[ core-sdf-grammar2rtg | error ] Resolution: please add a cons attribute to thisproduction.
[ core-sdf-grammar2rtg | error ] Production in abstract syntax:
        prod([lit("else")],cf(alt(lit("let"),alt(lit("in"),alt(lit("end"),alt(lit("while"),alt(lit("do"),alt(lit("function"),alt(lit("if"),alt(lit("then"),lit("else")))))))))),attrs([]))

problem arises in syntax definition of TIL