; IPL-I List Reversal Program
; This program reverses a list

START:
  H1 = L0         ; Initialize H1 to input list
  H2 = 0          ; Initialize H2 to empty list (accumulator)

LOOP:
  Q0 = H1         ; Test if H1 is empty
  J0 Q0, END      ; If empty, jump to END
  
  S1 = H1*        ; Get first element of H1
  H1 = H1'        ; Set H1 to rest of list
  
  H2 = S1:H2      ; Cons S1 onto H2
  J0 0, LOOP      ; Jump back to LOOP

END:
  OUT H2          ; Output reversed list
  HALT