code: static Span<Term> targetList2Span(List<Target> list) {
  	Span<Term> span = new Span<Term>();
  	for (Target target : list) {
  	    if (target.isHead()) {
  		span.addTarget(target.getTerm(), true);
  	    } else {
  		span.addTarget(target.getTerm());
  	    }
  	}
  	return span;
      }
docs: Converts a Target list into a Span of terms