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State machine (FSM) templates

Teaching Case — An Arrow to a State That Does Not Exist

One character changed: the transition out of `Paid` goes to `Shipd`. Every tool that draws what it is handed omits that arrow entirely — the renderer this engine replaces did `if (!a || !b) continue;` — so the figure showed a complete machine with one fewer edge, and nothing anywhere said an edge was missing. Here the arrow is drawn to a dashed box carrying the name that does not exist, and the reachability checks report a GAP rather than blaming the states the missing edge would have reached.

State machine (FSM)Flow & ProcessState machine (FSM) syntax docs
Template previewState machine (FSM)
Order lifecycle5 states · 4 transitions · 4 eventscheckoutpaymentdispatchdeliveredCartPendingPaidShippedDeliveredShipdnever declared1 statement in this machine cannot be true of any run.ERRORThe transition on line 13 names `Shipd`, which is never declared. The renderer this replaces DROPPED such an arrow from the drawing with no diagnostic, so a mistyped target produced acomplete-looking machine missing an edge nobody could see was missing.GAPReachability is UNCHECKED: one transition names a state that does not exist (line 13), so the machine this document describes is not the machine drawn. Correct it and every answer belowchanges.

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title "Order lifecycle"

state Cart
state Pending
state Paid
state Shipped
state Delivered final

initial Cart

transition Cart    -> Pending   on "checkout"
transition Pending -> Paid      on "payment"
transition Paid    -> Shipd     on "dispatch"
transition Shipped -> Delivered on "delivered"