External subobjects

External subobjects are objects, that are already provided during the evaluation of the current Fib object. (See the subobjects $Obj_o$ in section 9.9 on page )

Syntax: $Obj = sub( Number , ( V_1 , \ldots , V_n ) )$

Description of the elements:

• $Number$: The number of the external subobject (corresponding to an output variable vector in the next root-element), which is to be used here. The $Number$ can only be fixed integer value. The domain of the $Number$ is implicit in the number of external subobjects (or output variable vectors) of the next root-element (the root-element, in which the subelement appears in the main-Fib-object), see section 9.14 on page . If the value of the specified number is outside the valid domain (this is equivalent to an error), it is rounded to the next value, which lies in the domain.
• $( V_1 , \ldots , V_n )$: The vector with the output values, which are needed for the used Fib object.
• $V_i$: This are the output values, which are needed for the used Fib object. For them the output variables ( $OutVar_{i_Number}$) in the im external object element (obj) are defined. The output values have the same number and order as the $Number$'th output variables in the corresponding external object element (obj). Nevertheless, if the number does not match (equivalent to a faulty Fib object), the variables that are too much are ignored, and for the missing variables, the zero value of the domain of the corresponding output variable in the root-element is used.

Notes: With external subobjects multimedia information can be provided for the Fib object, which can be used in certain places. This is useful for example, if the current Fib object, implements a calculation or function, which is more extensive and is required several times in other Fib objects.

If an external subobject dosn't exists for the evaluation of a root element, an empty point $p()$ (point without impact) will be used for it. external subobjects can even be useful for the top most root-element, if for example the multimedia object $Obj$ is just a frame, in which an other picture can be displayed from an given start point (given by the output values).

Examples:

• $sub( 1 )$: At this point, the first external subobject of the next root-element is used.
• $sub( 1, x, y, r )$: At this point, the first external subobject of the next root-element is used. The variables $x$, $y$ and $r$ are provided for the external subobject. These variables could for example be used for the position $(x, y)$ and $r$ for the amount of red of the point, which is used for the external subobject.