What is the specific error in the following proof? How do we fix the error to make the proof correct? 

PHILOSOPHY (PREDICATE LOGIC ERROR)

A. What is the specific error in the following proof? How do we fix the error to make the proof correct?

1. (x)(Fx > Gx)
2. (x)Fx               /(x)Gx
3. Fa > Ga           UI, 1
4. Fa                    UI, 2
5. Ga                    MP, 3,4
6. (x)Gx                UG, 5

B. What is the specific error in the following proof? How do we fix the error to make the proof correct?

1. (x)(Fx > Gx)
2. (3x)Fx            /(3x)Gx
3. Fa > Ga           UI, 1
4. Fa                    EI, 2
5. Ga                   MP, 3,4
6. (3x)Gx             EG, 5

C. What is the specific error in the following proof? How do we fix the error to make the proof correct?

1. (x)(Fx > Gx)
2. (3x)Fx                /(3x)Gx
3. Fx                       EI, 2
4. Fx > Gx              UI, 1
5. Gx                      MP, 3,4
6. (3x)Gx                EG, 5