Diagnosis
The syntax check found an error. An object reference is expected at thecursor. However, no valid object reference was found.

System Response
The cursor shows where the error occurs in your entry.

Procedure
Objects in constraints are usually referred to by the class and classtype to which they are allocated:
(300)DESK
A variable is defined with the keyword IS_A:
D IS_A (300)DESK
If you want to refer to several objects, separate the objects with acomma.
If you define variables for characteristics, the characteristics areseparated with a semicolon.