### Abstract

We discuss an algebraic proof system that manipulates multilinear arithmetic formulas. We show this proof system to be fairly strong even when restricted to multilinear arithmetic formulas of a very small depth. Specifically, algebraic proofs manipulating depth 3 multilinear arithmetic formulas are strictly stronger than Resolution, Polynomial Calculus (and Polynomial Calculus with Resolution); and (over characteristic 0) admit polynomial-size proofs of the (functional) pigeonhole principle. Finally, we illustrate a connection between lower bounds on multilinear proofs and lower bounds on multilinear arithmetic circuits.