protected function parse_sibling() {
		if ((($this->pos + 1) < $this->size) && ($this->doc[$this->pos + 1] === '=')) {
			++$this->pos;
			return ($this->token = self::TOK_COMPARE_CONTAINS_WORD);
		} else {
			return ($this->token = self::TOK_SIBLING);
		}
	}