Logic and Philosophy, A. Hausman, H. Kahane, P. Tidman, Wadsworth, 11th ed., 2010, 13-1(1)

Prove valid:

1. Fa • (x)[Fx ⊃ (x = a)]
2. (∃x)(Fx • Gx)
3. ∴ Ga
4. Fm • Gm ......... 2 EI x/m
5. Fm ......... 4 Simp.
6. (x)[Fx ⊃ (x = a)] ......... 1 Simp.
7. Fm ⊃ (m = a) ......... 6 UI x/m
8. m = a ......... 5,7 MP
9. Gm ......... 4 Simp.
10. Ga ......... 8,9 Id