Your monad(WorldState, Value) example assumes shared global state. So not a networked system then? That's not a train-smash for your argument if you can show m

Your monad(WorldState, Value) example assumes shared global state. So not a networked system then? That's not a train-smash for your argument if you can show me a Mathematical model for a global mutex. When the discussion turns to control-flow you are inevitably in the land of well-ordered imperatives, not Mathematical, lazy-evaluated declaratives.