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SUMMARY:Contractibility of acyclic 2-complexes - Ian Leary (University of 
 Southampton)
DTSTART:20191122T134500Z
DTEND:20191122T144500Z
UID:TALK134200@talks.cam.ac.uk
CONTACT:76015
DESCRIPTION:The existence of an algorithm to decide\nwhether finite 2-dime
 nsional simplicial complexes\nare contractible is a notorious open problem
 . \nEquivalently\, can one decide whether a balanced\npresentation present
 s the trivial group? \nI will discuss this problem\, my solution to\nan an
 alogue for infinite complexes\, and a\nconnection with the Collatz conject
 ure.  
LOCATION:CMS\, MR13
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