After application of first step we get,
$ x " y (^~ (" z) P(f(x), y, z) Ú ($ u Q(x, u) & $ v R(y, v))))

After application of second step we get,
$ x " y ($ z ^~P(f(x), y, z) Ú ($ u Q(x, u) & $ v R(y, v)))

After application of fourth step (step 3 not required) we get,
" y (^~P(f(a), y, g(y)) Ú (Q(a, h(y)) & R(y, I(y)))

After application of fifth step we get,
" y ((^~P(f(a), y, g(y)) Ú Q(a, h(y)) & (^~P(f(a), y, g(y)) Ú R(y, I(y)))

After application of sixth step we get,
^~P(f(a), y, g(y)) Ú Q(a, h(y))
^~P(f(a), y, g(y)) Ú R(y, I(y))