NAME
     DefPropMol   - define molecule property
     DefPropRes   - define residue property
     DefPropAtom  - define atom property
     DefPropBond  - define bond property
     DefPropAngle - define angle property
     DefPropDist  - define distance property
     DefPropPrim  - define primitive property

SYNOPSIS
     DefPropMol propertyName expr
     DefPropRes propertyName expr
     DefPropAtom propertyName expr
     DefPropBond propertyName expr
     DefPropAngle propertyName expr
     DefPropDist propertyName expr
     DefPropPrim propertyName expr

DESCRIPTION
     Define a property with the given name by the given
     expression. See SelectMol for a description of the
     expression syntax. Properties can be used in other
     property definitions or selections. The Select
     commands are actually just special cases of the
     DefProp commands, they defines the property with
     the name "selected". The following properties are
     used internally by the program and should not be
     defined by this command:

	 all
	 visible

     The value of the "visible" property is maintained
     by the program, it is set for all atoms, bonds,
     distances and primitives that have their attributes
     (Style*) set in a way to make them visible. This is
     very convenient for selecting only visible items.

     The "displayed" property is used by the program to
     decide which items should be displayed. It is not
     recommended to modify it, it is normally better to
     use the Style* commands for changing the visibility.
     It is very useful for molecules, however, but the
     molecule dialog (DialMol command) is more convenient
     for modifying it in this case.

     The "movable" property is used by the program to
     decide which items are moved by rotations etc.
     It only has an influence for molecules, and the
     molecule dialog (DialMol command) command is more
     convenient for modifying it.

     Some properties are predefined, they can be seen
     in the file:

	 $MOLMOLHOME/setup/PropDef

     or with the HelpProp command.

EXAMPLES
     DefPropRes 'helix' 'num >= 47 & num <= 56'
     DefPropAtom 'helixCA' 'name = "CA" & res.helix'

SEE ALSO
     DialSelect, Select*, DialMol, HelpProp, ListProp*

DATE
     950704
