error: Symbol `ref` is referenced and thus cannot be purged
    at purge-ref.asm(4)
warning: Purging a label `OK` [-Wpurge]
    at purge-ref.asm(7)
error: Symbol `NotOK` is referenced and thus cannot be purged
    at purge-ref.asm(11)
error: Symbol `EvenLessOK` is referenced and thus cannot be purged
    at purge-ref.asm(15)
warning: Purging a label `Maybe` [-Wpurge]
    at purge-ref.asm(23)
Assembly aborted with 3 errors!