distribute_nt.bgf

<bgf:grammar xmlns:bgf="http://planet-sl.org/bgf">
  <bgf:production>
    <nonterminal>foo</nonterminal>
    <bgf:expression>
      <sequence>
        <bgf:expression>
          <nonterminal>bar</nonterminal>
        </bgf:expression>
        <bgf:expression>
          <choice>
            <bgf:expression>
              <nonterminal>qux</nonterminal>
            </bgf:expression>
            <bgf:expression>
              <nonterminal>wez</nonterminal>
            </bgf:expression>
          </choice>
        </bgf:expression>
      </sequence>
    </bgf:expression>
  </bgf:production>
</bgf:grammar>