Fundamental Theorem of Calculus/Second Part/Also presented as

Theorem
The Fundamental Theorem of Calculus can also be presented in the following form:

Let $f$ be a real function which is continuous on the closed interval $\closedint a b$ expressed as a normal first order ODE:
 * $(1): \quad \dfrac {\d y} {\d x} = \map f x$

Let $c \in \R$ be an arbitrary real number.

Then there exists a unique solution $\map F x$ to $(1)$ on $\closedint a b$ such that $\map F a = c$, given by the definite integral:
 * $\ds \map F x = c + \int_a^x \map f t \rd t$