deriv[?x] is the derivative of unary-scalar-function-quantity ?x {deriv[f[x]] = f'[x]}. Deriv is only defined on continuous functions.
Deriv has the normal algebraic properties of derivatives of real-valued functions; see the axioms for the exact behavior of differentiation with respect to sums and products of unary-scalar-function-quantities.
(Forall (?F ?G ?R) (=> (And (Unary-Scalar-Function-Quantity ?F) (Unary-Scalar-Function-Quantity ?G) (Real-Number ?R)) (And (= (Deriv (+ ?F ?G)) (+ (Deriv ?F) (Deriv ?G))) (= (Deriv (* ?F ?G)) (+ (* (Deriv ?F) ?G) (* ?F (Deriv ?G)))) (= (Deriv (Expt ?F ?R)) (* ?R (Expt (Deriv ?F) (1- ?R)))))))