The substitution inference rule is related to Leibniz’s Law.

# Leibniz’s Law

Leibniz’s Law: If $t1=t2$ is a theorem, then so is $P[t_{1}/x]⇔P[t_{2}/x]$. Leibniz’s Law is generally referred to as the ability to substitute “equals for equals”.

The substitution inference rule is related to Leibniz’s Law.

Leibniz’s Law: If $t1=t2$ is a theorem, then so is $P[t_{1}/x]⇔P[t_{2}/x]$. Leibniz’s Law is generally referred to as the ability to substitute “equals for equals”.