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. |
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