Thanks guys the tips made me have the idea that I can just write the check for the second list instead of '(true).
Here is my solution: #lang racket (define (test1 word book book2) (cond ((null? book) '(false)) ((equal? word (first book)) (cond ((null? book2) '(false)) ((equal? word (first book2)) 'true) (else (test1 word book (rest book2))))) (else (test1 word (rest book) book2)))) Thanks you again -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to racket-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.