Properties

{[<expression>]}

	<expression>	=	<and expression>
	<and expression>	=	<or expression> [&& <and expression>]
	<or expression>	=	<face expression> [$\vert\vert$ <or expression>]
	<face expression>	=	<not expression> [ <not expression> / <not expression>]
	<not expression>	=	! <not expression>
		=	<base expression>
	<base expression>	=	<property>
		=	( <expression> )

The <expression> is a boolean test that will accept or reject a conformation or a relation. The field may be empty, in that case every conformation or relation will be accepted whatever properties it has. With this kind of expression you can restrict your sets of conformations or relations without specifying all the elements. Per example:

Example:

{ saenger && ! ( XXII || XIX ) }

will give you a set of all Saenger relations without types XXII and XIX.