## Description

variableDef elements provide wiring information (i.e., they
identify the input and output signals used by these function
blocks). They also provide MathML content markup to indicate any
calculation required to arrive at the value of the variable,
using other variables as inputs. The variable definition can
include statistical information regarding the uncertainty of the
values which it might take on, when measured after any
calculation is performed. Information about the reason for
inclusion or change to this element can be included in an
optional provenance sub-element.
If either or both min or max attributes are specified, the
implementer must limit the final value of the variable to remain
within the specified bound(s). These attributes imply a one- or
two-sided limiter function downstream of any specified
calculation, input signal, or initial value.
Min and max attributes may only be fixed numeric values. To
provide variable limits, the modeler should employ the piecewise
MathML element in a calculation subelement.