## 2.2 Control

`<<leave>>`

  terminates the current loop

`<<next>>`

  goes on to the next iteration of the current loop

`<<named L>>`

  introduces variable L to refer to the current loop

`<<leave L>>`

  terminate the loop referred to by `L`

`<<next L>>`

  goes on to the next iteration of the loop referred to by `L`

`<<while B>>`

  equivalent to `if B then skip else <<leave>> end`

`<<until B>>`

  equivalent to `if B then <<leave>> end`