BaraksAssOneScheme

#lang racket

(define foo (lambda (x s)

              (if (list? s)

                  (if (< (length s) 2)
                      '()

                      (if (list? (first s))

                          (append (foo x (first s)) (foo x (rest s)))

                          (if (equal? x (first s))
                              (append (list (second s)) (foo x (rest s)))
                              (foo x (rest s))
                              )
                          )
                      )

                 '()
              )
            )
)

(foo 'y '(y (3 y 5 y y 8 9) (10 y 12 13 y 15 y) 17))