There's no side effects in f here, so the statement does not apply
Parent said
> State is in practice always subjected to side effects and concurrency.
There was never any claim or assumption regarding f. Maybe the way you interpreted it is what they meant, but it is not what was stated.
Parent said
> State is in practice always subjected to side effects and concurrency.
There was never any claim or assumption regarding f. Maybe the way you interpreted it is what they meant, but it is not what was stated.