Transitions

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Adding transitions

→ Press T for the transition tool (cursor becomes crosshair)

→ Click and drag from one state to another (a dashed preview line follows your cursor)

→ Release over the target state to create the transition; release over empty space to cancel

→ A label editor opens automatically on creation. Type your symbol(s) and press Enter to confirm, or Escape to cancel

→ Drag from a state back to itself for a self-loop (rendered as a curved path above the state)

→ On touch devices, the same drag gesture works: tap a state and drag to the target

Duplicate handling

→ For DFA, NFA, Mealy, and Moore modes: if a transition between two states already exists, dragging between them opens the existing transition for editing instead of creating a duplicate. This lets you add more symbols to the same edge.

→ For PDA and TM modes: multiple transitions between the same pair of states are allowed (since each has different read/pop/push or read/write/move specifications). Each creates a separate edge.

→ Multiple self-loops on the same state stack vertically; each loop is offset 18px higher than the previous, with spread increasing by 4px per loop

Editing transitions

→ Click a transition edge or label to select it (highlighted in accent color with a brighter arrowhead)

→ Double-click a transition to edit the label inline

→ Separate multiple symbols with commas: a, b, c

→ Right-click a transition for Edit Label / Delete options

→ Bidirectional transitions (A→B and B→A both exist) automatically curve with a 20px offset to avoid overlap

→ The label editor shows a placeholder hint based on the current mode (e.g., a, Z → AZ for PDA, a → b, R for TM)

Default symbols by mode

When a new transition is created, it gets a default symbol based on the current mode:

→ DFA: a

→ NFA: ε (epsilon transition)

→ PDA: a, Z → Z

→ TM: a → a, R

→ Mealy: a/0

→ Moore: a (output is in the state label)

Transition format reference