Definition block of global named constants, quantitties, expressions,
positions and rotations which may be used by name or
by a reference in scope of the current document
The global complex type is defined in order to reuse this defintion
in derived schemas
Named constant
Named variable
Named matrix
Named quantity
Named expression, may contain other named constants,
quantities and expressions
Named cartesian position, default unit mm
Named cartesian rotation, default unit radian
Named cartesian rotation, default unit radian