The propositional rules of derivation carry over unchanged into Predicate Logic
Proofs
The propositional rules of inference are used unchanged in predicate logic.
Derive
a) Fa ∴ ∼ ∼ Fa
b) ∴ ∼ (Fb. ∼ Fb)
c) ∼ Fm. ∼ Gn∴ ∼ (Fm∨Gn)
d) (Fa.Fa)∨(Gb.Gb)∴ Fa∨Gb
e) Fb⊃(Ga⊃Hc), Fb⊃Ga ∴ Fb⊃Hc
f) Fa∨Gb, Gb⊃Hd ∴ ( ∼ Fa⊃Hd)
g) (Fa⊃Gb).(Gb⊃Fa) ∴ Fa≡Gb