States

auto state Closed
    on enter
        business.open = false
    end
end

state Open
    on enter
        business.open = true
    end
    on building.visitorEntered
        business.visitors += 1
    end
    on exit
        log("closing, {business.visitors} visitors today")
    end
end

A state holds event handlers, timer handlers, on enter and on exit.
auto state is the starting state; a script has at most one. In a new instance its on enter runs in the start transaction (Lifecycle). This way a business that starts closed has business.open == false, whatever the contract's default.
Handlers outside any state belong to the empty state. A script with no states at all is valid.
An event goes to the handler in the current state, or else to the one in the empty state; if neither exists, it is ignored. An instance takes the same event at most once.
enter and exit are written only inside a state; ready and migrate only at the script's level.

goto

goto Name moves to another state. A goto to the current state does nothing: a repeated decision does not run the entry again.
Moving on runs, in order: the old state's on exit → the move → the new state's on enter. All of it is in the current transaction, and the handler goes on in the new state after the goto.
goto is not allowed inside on enter and on exit, nor in anything they call; the compiler follows the calls to check.
If exit or enter fails, the whole transaction is undone and the state stays as it was; then the error policy applies.

goto​

goto