public void accept(@NotNull PsiElementVisitor visitor) {
if (visitor instanceof BnfVisitor) ((BnfVisitor) visitor).visitExternalExpression(this);
else super.accept(visitor);
}
public void accept(@NotNull PsiElementVisitor visitor) {
if (visitor instanceof BnfVisitor) ((BnfVisitor) visitor).visitParenthesized(this);
else super.accept(visitor);
}