BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251021T203909EDT-82107sgbFC@132.216.98.100 DTSTAMP:20251022T003909Z DESCRIPTION:Title: Coequalizers and free triples\, II (continued)\n\nAbstra ct: This paper studies a category X with an endofunctor T : X o X. A T-alg ebra is given by a morphism Tx o x in X. We examine the related questions of when T freely generates a triple (or monad) on X\; when an object x in X freely generates a T-algebra\; and when the category of T-algebras has c oequalizers and other colimits. The paper defines a category of ``T-horns' ' which effectively contains X as well as all T-algebras. It is assume tha t Xs is cocomplete and has a factorization system (E\,M) satisfying reason able properties. An ordinal-indexed sequence of T-horns is then defined wh ich provides successive approximations to a free T-algebra generated by an object x in X\, as well as approximations to coequalizers and other colim its for the category of T-algebras. Using the notions of an M-cone and a s eparated T-horn it is shown that if X is M-well-powered\, then the ordinal sequence stabilizes at the desired free algebra or coequalizer or other c olimit whenever they exist. This paper is a successor to a paper written b y the first author in 1970 that showed that T generates a free triple when every x in X generates a free T-algebra. We also consider colimits in tri ple algebras and give some examples of functors T for which no x in X gene rates a free T-algebra.\n DTSTART:20191029T183000Z DTEND:20191029T193000Z LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:M. Barr\, 9IÖÆ×÷³§Ãâ·Ñ URL:/mathstat/channels/event/m-barr-mcgill-302022 END:VEVENT END:VCALENDAR