LetExp([
 FunctionDec[
  (f,[
   (x1,true,int),
   (x2,true,int),
   (x3,true,int),
   (x4,true,int),
   (x5,true,int),
   (x6,true,int)],
   SOME(int),
   OpExp(PlusOp,
    VarExp(
     SimpleVar(x1)),
    VarExp(
     SimpleVar(x3)))),
  (printint,[
   (i,true,int)],
   NONE,
   LetExp([
    FunctionDec[
     (f,[
      (i,true,int)],
      NONE,
      IfExp(
       OpExp(GtOp,
        VarExp(
         SimpleVar(i)),
        IntExp(0)),
       SeqExp[
        CallExp(f,[
         OpExp(DivideOp,
          VarExp(
           SimpleVar(i)),
          IntExp(10))]),
        CallExp(print,[
         CallExp(chr,[
          OpExp(PlusOp,
           OpExp(MinusOp,
            VarExp(
             SimpleVar(i)),
            OpExp(TimesOp,
             OpExp(DivideOp,
              VarExp(
               SimpleVar(i)),
              IntExp(10)),
             IntExp(10))),
           CallExp(ord,[
            StringExp("0")]))])])]))]],
    IfExp(
     OpExp(LtOp,
      VarExp(
       SimpleVar(i)),
      IntExp(0)),
     SeqExp[
      CallExp(print,[
       StringExp("-")]),
      CallExp(f,[
       OpExp(MinusOp,
        IntExp(0),
        VarExp(
         SimpleVar(i)))])],
     IfExp(
      OpExp(GtOp,
       VarExp(
        SimpleVar(i)),
       IntExp(0)),
      CallExp(f,[
       VarExp(
        SimpleVar(i))]),
      CallExp(print,[
       StringExp("0")])))))]],
 CallExp(printint,[
  CallExp(f,[
   IntExp(1),
   IntExp(2),
   IntExp(3),
   IntExp(4),
   IntExp(5),
   IntExp(6)])]))