Hypothetical Syllogism/Formulation 2/Proof 1

Theorem

 * $p \implies q, q \implies r, p \vdash r$

Proof

 * align="right" | 4 ||
 * align="right" | 1, 2
 * $p \implies r$
 * Sequent Introduction
 * 1, 2
 * Hypothetical Syllogism: Formulation 1
 * Hypothetical Syllogism: Formulation 1