two-in-a-row?です (define two-in-a-row? (letrec ((W (lambda (a lat) (cond ((null? lat) #f) (else (let ((nxt (car lat))) (or (eq? nxt a) (W nxt (cdr lat))))))))) (lambda (lat) (cond ((null? lat) #f) (else (W (car lat) (cdr lat))))))) two-in…