Identity and Theorems of Logic - Lecture 10 (Logic)

Adding identity to first-order predicate logic introduces how many new rules of derivation?

1. A.Three — one for reflexivity, symmetry, and transitivity
2. B.Two — a substitution rule and a reflexivity rule
3. C.One — rule I, which covers both reflexivity and substitution of equals
4. D.Zero — identity is fully captured by the existing rules