Construct:	atsign ('@')

Description:	In parallel GENESIS the '@' is used to specify
		particular nodes on which an operation is to be
		performed or on which an element resides.  Note
		that this use of the '@' symbol	does not conflict
		with the use of '@' as a string	concatenation
		operator, which is still preserved.

Usage:
		The '@' is followed by a node list, defined as followed:

			<node-list> <- <node-spec>,<node-spec>,...
		
			<node-spec> <- <node>[.<zone>]

		where <node> is the znode number for the node, that is
		its number within its zone.  If .<zone> is omitted,
		the zone of the caller is assumed.  Any command or
		element without the @ extension is assumed to
		be on the local node. If the node and zone are the
		same as the caller's, the command is executed locally.  

		Nodes and zones are identified at present as an integer
		(znode number or zone number) or one of two keywords:

			other  :  All except the caller's ("others"
				  also accepted).
			all    :  All including the caller's.

		Thus "@other" means all nodes in the caller's zone
		except the caller's node.  "@other.all" means every
		node in the parallel platform except the caller's.
		"other.other" means every node in every other zone
		except the nodes whose znode number is the same as
		the caller's znodenumber.  "@all.all" means every node
		in the parallel platform.  "@all.other" means every node
		in every other zone.  If "other" is given for node then
		there must be a node whose znode number corresponds
		to the caller's znode number in every zone that is specified.
		There must exist at least one node in each node-spec.

Examples:	createmap@1,2 /neutral /array 10 10
		createmap@other /neutral /array 10 10
		addmsg /cell1 /cell2@2 SPIKE

See also:	raddmsg, async, rvolumeconnect, rvolumeweight, rvolumedelay
		



(C) Pittsburgh Supercomputing Center (PSC)
Revised: Sep 3, 1996
URL file://www.psc.edu/general/software/packages/genesis/atsign.txt
