Given an Archimedean ordered field$F$, the Newton–Leibniz operator or D operator$\tilde{D}: D^1(F, F) \to (F \to F)$ is a function from the type of differentiable functions $D^1(F, F)$ to the type of functions $F \to F$. For any differentiable function $f:D^1(F, F)$, the function $\tilde{D}(f)$ is called the derivative of $f$.