def ptbunescape(token):
	"""Unescape brackets in a single token, including PTB notation."""
	if token in ('', '#FRONTIER#', None):
		return None
	elif token == '-LCB-':
		return '{'
	elif token == '-RCB-':
		return '}'
	elif token == '-LSB-':
		return '['
	elif token == '-RSB-':
		return ']'
	return token.replace('-LRB-', '(').replace('-RRB-', ')').replace(
			'#LRB#', '(').replace('#RRB#', ')')