The rule specified with %start is a legal topmost
production rule, but the first rule in a BNF file is
still used as bovine-toplevel. This is not made clear.
If a rule is specified with %scopestart then that rule
is not used/generated in the corresponding table. This
leads to an erroneous disconnected grammar
specification. I think that the use of this variable
needs to be reviewed and its documentation needs to be