node PrintArmNode {
  in arm: Arm
}

node PrintBodyNode {
  out left_arm: Arm
  out right_arm: Arm
}

tree main = Sequence {
  PrintBodyNode (left_arm -> left_arm, right_arm -> right_arm)
  Sequence {
    PrintArmNode (arm <- left_arm)
    PrintArmNode (arm <- right_arm)
    PrintStringNode (input <- "literal message")
  }
}