s.types[i] = AN
			}
		}
	}

	// Rule W5.
	for i, t := range s.types {
		if t == ET {
			// locate end of sequence
			runStart := i
			runEnd := s.findRunLimit(runStart, ET)

			// check values at ends of sequence
			t := s.sos
			if runStart > 0 {
				t = s.types[runStart-1]
			}
			if t != EN {
				t = s.eos
				if runEnd < len(s.types) {