3 added 52 characters in body edited Aug 11 '15 at 18:19 zagadka314 1671212 bronze badges The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` Just type the same exact thing you see in question 10.26, then select "FO Con" without any premises. This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later inI assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section. See the text, and I will update thisvery impressive answer when I come to that section. above instead! The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` Just type the same exact thing you see in question 10.26, then select "FO Con" without any premises. This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section. The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` Just type the same exact thing you see in question 10.26, then select "FO Con" without any premises. This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section. See the very impressive answer above instead! 2 Made my answer more clear edited Jul 12 '15 at 17:30 zagadka314 1671212 bronze badges The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` Just type the same exact thing you see in question 10.26, then select "FO Con" without any premises. This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section. The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section. The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` Just type the same exact thing you see in question 10.26, then select "FO Con" without any premises. This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section. 1 answered Jul 10 '15 at 21:50 zagadka314 1671212 bronze badges The solution to 10.26. You will hit yourself for this, if you are as lost as I was!! ``````|_ |∀x Tet(b) ↔ ∃w Tet(b) FO Con `````` This still doesn't answer the question about how to use ∀ Intro and ∃ Elim, but it answers how to solve 10.26. I assume that ∀ Intro and ∃ Elim are covered later in the text, and I will update this answer when I come to that section.