alice-teacher Proximity problem

[dorlik at wildwood.org]

My student is trying to build a game in which the player slays trolls with a sword. It seemed like a simple "if sword is within ,07 meters of troll" "do together Health cube showing is false"
However, we cannot get it to work. Nothing changes when the player slashes the troll with the sword Suggestions? 

Sent from my very cool iPhone
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