## Slots on this class:

**Documentation: **
If ?x is defined over some dense interval of ?t, then
there are a finite number of points at which ?t is not
continuous.

**Subclass-Of: **Function-quantity

## Notes:

- A piecewise continuous quantity need not have a well defined value at
a time point. One needs to know the direction as well (from left or
right). Is is that the value not well defined, or is the means of
finding the value not well defined?

- Note that the derivative of a standard-quantity may be a
piecewise-continuous-quantity.