Im stuck and cant seem to find a way to continue

pr-∀x(F(xa(x))→∼F(xx))

show∴ ∼∃x∀yF(a(x)y

QN is disabled. Use UI, EI, and EG in the derivation

1. show∼∃x∀yF(a(x)y2. -------

∃x∀yF(a(x)y)Ass id

3.--------∀yF(a(i)y)2 ei

4.--------F(a(i)a(i))3 ui

5.--------∀x(F(xa(x))→∼F(xx))pr

6.--------F(a(i)a(a(i)))→∼F(a(i)a(i))5 ui

7---------∼∼F(a(i)a(i))4 dn

8---------∼F(a(i)a(a(i)))6 7 mt

9 --------∃x∼F(xa(x))8 eg

I dont know how to continue

Any advice will be appreciated, Thnx