[antlr-interest] odd nondeterminism

[Paul J. Lucas]

	Given:

		expr : exprSingle (sortByClause)? ;

		sortByClause : SORT BY '(' sortSpec ')' ;

	I get:

		warning:nondeterminism between alts 1 and 2 of block
		upon k==1:SORT

	but I don't understand why.  SORT appears nowhere else in the
	grammar.

	- Paul