def props_of_this_event(event, ts_tuple, run):
	"""
	Find the set of propositions that correspond to an event.

	Parameters
	-----------
	event: A tuple
		An event is a tuple of the form (agent_no, run_pos). This argument
		can either be a tuple of events (simultaneous events) or a tuple of
		integers (single event).

	ts_tuple: A tuple of transition system objects
		In this tuple ts_tuple[i] corresponds to the transition system that
		models agent i.

	run: A list of tuples.
		A run on the team transition system. Length of the list is the length
		of the run, and the i^th tuple run[i] gives the state of the team at
		the i^th position of the run. Length of this tuple is equal to the number 
		of the agents and the j^th element run[i][j] of this tuple gives the
		state of the j^th agent at the i^th position of the run.

	Returns
	-------
	props: The set of propositions.

	"""

	# Construct a serialized list of events
	events_ser = [ee for ee in event]

	# Construct the set of propositions of the states of the agents
	props = set()
	for e in events_ser:
		# NOTE: run[pos][agent] = state_label
		state = run[e.pos][e.agent]
		props |= ts_tuple[e.agent].g.node[state].get('prop',set())

	return props