This looks to me like a linked expression requiring special margins. It is displayed. The signs of comparison are vertically aligned in print. Only on the first line is the sign of comparison preceded by an expression on its left. Calling it a proof does not change the format defined by the Nemeth Code.
I would start the "proof" in cell 5 (2 cells to the right of the runover margin) with all of the comparison signs aligned in cell 7 -- runovers to both the anchor and the links will be in cell 9. A tn similar to the following may precede your "proof".
Each step in the print expression is followed by a blank to be filled in except for the final step.
I am attaching a word document with my suggestion in simbraille.