We show that every resolution proof of the functional version FPHPnm of the pigeonhole principle (in which one pigeon may not split between several holes) must have size exp(Omega(n/(log m)(2))). This implies an exp(Omega(n(1/3))) bound when the number of pigeons m is arbitrary. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 21]
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