*Structure Class* **RULE**

## Package:

`CL-SBML`

## Class Precedence List:

RULE, SBML-BASE, STRUCTURE-CLASS, T.

## Slots:

- FORMULA: default value "", type STRING, initarg :FORMULA
- MATH: default value NIL, type CONS, initarg :MATH

## Description:

The instances of this structure class represent SBML rule definitions.

Rules provide a way to create constraints on variables for cases in which the constraints cannot be expressed using reactions nor the assignment of an initial value to a component in a model.

The RULE class is used as a mixin for more specialized classes. Hence there is no constructor available for it.

The accessors RULE-FORMULA, and RULE-MATH are used to extract and set the structure fields.

## Affected By:

None.

## Exceptional Situations:

None.

## See Also:

SBML-BASE, RULE-P, RULE-FORMULA, and RULE-MATH.

## Notes:

None.