#lang racket

(define funkcja
  (lambda (x)
    (+ (* x x) 3)))

(define calka
  (lambda (f p k n)
    (let ([dx 0]
          [l p]
          [w 0])
      (lambda wew
       (set! dx (/ (- k p) n))
      (if (= l p)
          ((set! w (+ w (/ (f l) 2))) (set! l (+ p 1)) (wew))
          (if (< l k)
              ((set! w (+ w (f l))) (set! l (+ l 1)) (wew))
              ((set! w (* dx (+ w (/ (f l) 2)))))
        ))))))

(calka funkcja 2 11 3)