At: "035.hac":4:
parse error: syntax error
parser stacks:
state	value
#STATE#	(null) 
#STATE#	(null) 
#STATE#	(null) 
#STATE#	keyword: defproc [4:1..7]
#STATE#	identifier: sum_diff [4:9..16]
#STATE#	( [4:17]
#STATE#	(chan-type) [4:18..27]
#STATE#	list<(port-formal-id)>: (port-formal-id): identifier: L1 ... [4:29..30]
#STATE#	, [4:31]
#STATE#	keyword: chan [4:33..36]
in state #STATE#, possible rules are:
	port_formal_id_list: port_formal_id_list ',' . port_formal_id  (#RULE#)
acceptable tokens are: 
	ID (shift)
