Joost J. Joosten Propositional Proof Systems and Fast Consistency Provers. 381-398 2007 48 Notre Dame J. Formal Log. 3 https://doi.org/10.1305/ndjfl/1187031410 https://www.wikidata.org/entity/Q119846391 db/journals/ndjfl/ndjfl48.html#Joosten07