Wrong. You mentioned that the set that I had applied, was applied to the wrong form.
However, I had not applied the set including the x^n term at the beginning, that you claimed that I had applied.
Simply, the three items seen at the beginning, are only suggestions as I pointed out in the same image.
[Again, notice that the particular collapser set of mine that I applied, worked successfully to produce the correct result.] 
It looks like you misread my rule set, and then ironically misplaced your misunderstanding, as my supposed error.
~God shall overlook your earlier accusations.