Understanding Symbolic Logic, Virginia Klenk, 5th ed., Pearson Prentice Hall, 2008, Unit 18, Ex. 2a, p. 354

 Prove the theorem.

1.     (x)(y)Fxy 2.     (y)Fmy 3.     Fmr 4.     (∃y)Fmy 5.     (∃x)(∃y)Fxy 6.     (x)(y)Fxy ⊃ (∃x)(∃y)Fxy

/(x)(y)Fxy ⊃ (∃x)(∃y)Fxy ACP 1 UI 2 UI 3 EG 4 EG 1-5 CP