(define (a)
  (b)    ; tail call
)

(define (c condition)
  (if condition
      (d) ; tail call
      (e) ; tail call
  )
)

(define (f)
  (g     ; tail call
    (h)  ; non tail call
    (i)  ; non tail call
   )
)

(define (j)
  (let ((n (k)))  ; k is a non tail call
    (l n)         ; a tail call
  )
)