This argument should be a simple variable name, not an expression. It must also be modifiable, hence it can't be a constant.
If the global variable is already in use, anything attached to it at the moment BOOK_MATRIX is called will be deleted. In particular, if the global variable is already a matrix, then the matrix is first deleted before a newly created matrix is associated with the global variable.
This argument is mandatory.
Each parameter of this kind should be of type Number. One such argument is mandatory. These arguments are not modified by the procedure.
Formatted on 21/01/18 at 16:55.