x1;; The first three lines of this file were inserted by DrRacket. They record metadata ;; about the language level of this file in a form that our tools can easily process. #reader(lib "htdp-intermediate-lambda-reader.ss" "lang")((modname memberOf) (read-case-sensitive #t) (teachpacks ((lib "docs.rkt" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "docs.rkt" "teachpack" "htdp")) #f))) ; checks if is a member of the list , prints either #true or #false ; this is a "shallow" recursive function (define (memberOf? x y) (cond ((null? y) #f) ((equal? x (car y)) #t) (else (memberOf? x (cdr y))) ) ) (memberOf? 2 '(1 4 2 3)) (memberOf? '(2) '(1 4 2 3)) (memberOf? 2 '(1 4 (2 3))) (memberOf? '(2) '(1 4 (2 3))) (memberOf? '(2 3) '(1 4 (2 3))) (memberOf? '(3 2) '(1 4 (2 3))) (memberOf? '(1 4) '(1 4 (2 3)))