I think it is the other way around. FRP goes further than state machines, in that it forbids any side effects. E.g. you could build a state machine that, when

I think it is the other way around. FRP goes further than state machines, in that it forbids any side effects. E.g. you could build a state machine that, when in a certain state and getting a certain event, responds or acts by printing the current time. A classical state machine will thus behave different, depending when it receives the event. However, in FRP you _must_ either parametrize the event with the current time, or you need to have something _outside_ of the statemachine (such as an effect interpreter) which handles effects such as printing the current time. A classic state machine does not have these restrictions.