10.1184/R1/6492233.v1 Sieg Sieg Mechanisms and search : aspects of proof theory Carnegie Mellon University 1992 Proof theory. 1992-01-01 00:00:00 Journal contribution https://kilthub.cmu.edu/articles/journal_contribution/Mechanisms_and_search_aspects_of_proof_theory/6492233 Department of Philosophy technical report