Light Up Satisfy Case Rule Bug

[charlestian23]

The last step in the given proof is incorrectly marked as valid. However, if the lightbulb to the right of the top middle 2 in the second-to-last step is removed, then the last step is correctly marked as invalid.

Light Up - Case Rule (accepts only branch when there are more).zip

[charlestian23]

A possible solution to this is just to disable using case rules as justification for the arrows. For example, if a user tries to click on a case rule to justify an arrow, we can just have an error message pop up.

[Bram28]

@charlestian23 But that is of course just a band-aid .. there is something inherently wrong with the logic here: it makes no sense that the placement of that bulb to the right of the top middle 2 in the second-to-last step would effect the validity of the last step