Computing definite integrals in Standard ML programming language.

Please don't give math proofs, the answer is a ML function named "integrate" that given a function, a, b, and n can calculate a definite integral.

3 Question 3 Your task is to write a function that compute a definite integral, namely, where f is an arbitrary continuous unary function. Naturally, you should provide a numerical solution using a simple method such as the trapezoidal method over a collection of boxes that sub-divide the integration interval Da, b). Formally, given f, a, b and na, subdivide the range la, bl into n sub-intervals (of width and compute the integral as the sum of the surfaces of the trapezoid embedded in each sub-interval. fun integrate f a b n