6.3.x. Exercise questions

Use the system of derivations to establish each of the following:
1. Fa → Ga, Fa, a = b ⊨ Gb
2. Fa → Ga, Fb, a = b ⊨ Ga
3. Fa ∧ a = gb ⊨ ¬ F(gc) → ¬ b = c
4. Fa → G(fa), G(fb) → Hb, a = b ⊨ Fb → Ha
5. fa = b, fc = d ⊨ (a = c ∨ b = d) → fa = d
6.

The vice president is Joe Biden

Barack Obama is the president

The vice president is not from Illinois


If Barack Obama is from Illinois, then Joe Biden is not the president

For more exercises, use the exercise machine.

Glen Helman 11 Jul 2012