let(a,1):

let(b,{
  print_1 + }occult([a]){ +
  block({
    print_ }}occult(occult([a])){{
  }) +
  block({
    print_iff(1,{ }}}occult(occult(occult([a]))){{{ },{-1}) 
  })
}):

print_[b] ,\n:

print_block([b])