mod DUPLICATE-TEN is
    inc LOOP-MODE .
    pr MACHINE-INT .
    op <_;_> : QidList MachineInt -> State .
    op init : -> System .
    vars Input StoredInput Output : QidList .
    vars QI QI0 QI1 QI2 QI3 QI4 QI5 QI6 QI7 QI8 QI9 : Qid .
    var Counter : MachineInt .
    rl [init] :
       init => [nil, <  nil ; 0 >, nil] .
    rl [in] : 
       [QI Input, < StoredInput ; Counter >, Output] 
       => [Input, < StoredInput QI ; Counter + 1 >, Output] .
    rl [out] :
       [Input, 
        < QI0 QI1 QI2 QI3 QI4 QI5 QI6 QI7 QI8 QI9 StoredInput ; Counter >, 
        Output] 
       => [Input, 
           < StoredInput ; Counter - 10  >, 
           Output QI0 QI1 QI2 QI3 QI4 QI5 QI6 QI7 QI8 QI9] .
  endm

  loop init .

  cont .
  
  *** result System: [nil,< nil ; 0 >,nil]

  (a b)

  cont .
  
  *** result System: [nil,< 'a 'b ; 2 >,nil]

  (c d e f g h i)

  cont .
  
  *** result System: [nil,< 'a 'b 'c 'd 'e 'f 'g 'h 'i ; 9 >,nil]

  (j k l)

  *** a b c d e f g h i j

  cont .
  
  *** result System: [nil,< 'k 'l ; 2 >,'a 'b 'c 'd 'e 'f 'g 'h 'i 'j]

  (m n)

  cont .
  
  *** result System: [nil,< 'm 'n ; 2 >,nil]