type list {
  nil : list;
  cons : (*, list) → list;
}

function mklst(integer) : list;
function mklst2(integer) : list;
function append(list, list) : list;
function flatten(list) : list;
function main() : *;

function mklst(integer) : list {
  tmp[0] = 0;
  tmp[1] = arg[0];
  tmp[0] = eq tmp[1] tmp[0];
  br tmp[0] {
    true: {
      prealloc 1, live: (arg[0]);
      tmp[0] = alloc nil ();
      ret tmp[0];
    };
    false: {
      tmp[0] = 1;
      tmp[1] = arg[0];
      tmp[0] = sub tmp[1] tmp[0];
      tmp[0] = call mklst (tmp[0]), live: (arg[0]);
      prealloc 3, live: (tmp[0], arg[0]);
      tmp[1] = arg[0];
      tmp[0] = alloc cons (tmp[1], tmp[0]);
      ret tmp[0];
    };
  };
}

function mklst2(integer) : list {
  tmp[0] = 0;
  tmp[1] = arg[0];
  tmp[0] = eq tmp[1] tmp[0];
  br tmp[0] {
    true: {
      prealloc 1, live: (arg[0]);
      tmp[0] = alloc nil ();
      ret tmp[0];
    };
    false: {
      tmp[0] = 1;
      tmp[1] = arg[0];
      tmp[0] = sub tmp[1] tmp[0];
      tmp[0] = call mklst2 (tmp[0]), live: (arg[0]);
      tmp[1] = arg[0];
      tmp[1] = call mklst (tmp[1]), live: (tmp[0], arg[0]);
      prealloc 3, live: (tmp[0], tmp[1], arg[0]);
      tmp[0] = alloc cons (tmp[1], tmp[0]);
      ret tmp[0];
    };
  };
}

function append(list, list) : list {
  tmp[0] = arg[0];
  case[list] tmp[0] {
    nil: {
      nop;
      tmp[0] = arg[1];
      ret tmp[0];
    };
    cons: {
      nop;
      tmp[0] = arg[1];
      tmp[1] = arg[0].cons[1];
      tmp[0] = call append (tmp[1], tmp[0]), live: (arg[0], arg[1]);
      prealloc 3, live: (tmp[0], arg[0], arg[1]);
      tmp[1] = arg[0].cons[0];
      tmp[0] = alloc cons (tmp[1], tmp[0]);
      ret tmp[0];
    };
  };
}

function flatten(list) : list {
  tmp[0] = arg[0];
  case[list] tmp[0] {
    nil: {
      ret tmp[0];
    };
    cons: {
      nop;
      tmp[0] = arg[0].cons[1];
      tmp[0] = call flatten (tmp[0]), live: (arg[0]);
      tmp[1] = arg[0].cons[0];
      tcall append (tmp[1], tmp[0]);
    };
  };
}

function main() : * {
  tmp[0] = 4;
  tmp[0] = call mklst2 (tmp[0]);
  trace tmp[0];
  tmp[0] = call flatten (tmp[0]);
  trace tmp[0];
  nop;
  tmp[0] = void;
  ret tmp[0];
}