Problem with transition rule (15) in 5. Animation Blueprint - Idle and Walk States

I cannot find a symbol to end the transition rule (point 5) of the tutorial 5. Animation Blueprint - Idle and Walk States. This symbol is a sort of vertical bar with a box below and the equal sign next to it. Can you help me? thanks!

Hi,Not sure if you still need this but,
it falls under boolean section let me know if you get the transition states to work coz im stuck on them

280303-screenshot-5.png