**Documentation:**A STANDARD-QUANTITY is everywhere continuous, has a piecewise continuous derivative, and a dimension. Quantities in QPT and QPC are standard-quantities. In QSIM, the derivatives are continuous as well within a behavior.

**Subclass-Of:**Everywhere-continuous-quantity

**D/Dt:***Slot-Cardinality:*1*Slot-Value-Type:*Piecewise-continuous-quantity

(<=> (Standard-Quantity ?X) (And (Everywhere-Continuous-Quantity ?X) (Value-Type ?X D/Dt Piecewise-Continuous-Quantity) (Value-Cardinality ?X D/Dt 1)))