At level 12 there are two red doors.
The right door contains the dot operation, the left door contains the rest of the level.
If I follow the the left door, I quickly get stuck at the 'isOver' puzzle, since the dot operation is needed here. However, I am not able to go back to the red doors in order to enter the left one, since the text is removed and I cannot cross the gap.
How do I get back to the red doors so I can get the dot operator?