Symbols

Symbol	Context	Usage
*	*<Class>	create instance
	restriction	select all instances
	projection	select all attributes
	*I<n> projection	project all identifer attrs
	computation	type specific op (multiply)
=	all	scalar value assignment
#=	all	table value assignment
#.=	all	assign at most one tuple
.=	all	assign at most one instance
..=	all	assign 0, 1 or many instances
0	restriction	select no instances
1	restriction	select at most one instance
*In	projection	project all In attributes
-attr	projection	select all but attr
~	path	repeated hopping
->	all	send signal
@	all	time of signal delivery
=>	all	asynch bridge
:	restriction	equals, matches
:	projection	rank delimiter
;	table definition	row delimiter
!=, ==, <, >, <=, >=	all	comparison
<name>	after action same line	set sequence token
<name>	before action same line	token enables action
<>, `	<>	, <>
<, <_, _>, >	between table values	set comparison
//	all	comment
&	&R<num>	relate instances
&	before assoc class	initialize assoc class attrs
!&	all	unrelate
!	(!boolean scalar)	not
!	scalar1!scalar2 =	assign true and false
;	all	separates actions and indicates no flow dependency between them on one line
/	all	hop across relationship
^+, ^-	before item in restriction	greatest, least
^+, ^-	after : in projection	rank ascending, descending
^>, <^, _>, <_	all	next greater, next lesser
^, +, *, - --	all	set operation on table value
+=, -=	all	combine assignment
#!!	all	image operation (see c.j. date)
^, +, -	between table values	set operations
#[ ]	#= assignment	table constructor