[antlr-interest] Strange ambiguous decision warning

[Jeroen Steenbeeke]

I simplified your grammar a bit to illustrate the problem
> sequenceType    :    (EMPTY_SEQUENCE '(' ')')
>                         | (itemType occurrenceIndicator) => (itemType 
> occurrenceIndicator)
>                       | itemType ;
> itemType    :    atomicType ;
> atomicType    :    qNameOrIdent ;
> qNameOrIdent    :    EMPTY_SEQUENCE;
Every single choice in sequenceType can start with EMPTY_SEQUENCE, so 
ANTLR does not have a clue which one to pick.