Amador Martin-Pizarro (Albert-Ludwigs-Universität Freiburg):
Equational and non-equational theories
Thursday, 17.10.2019 11:00 im Raum SR 1D
A first-order theory is equational if every definable set is a Boolean combination of instances of equations, that is, of formulae such that the family of finite intersections of instances has the descending chain condition. Equationality is a strengthening of stability yet so far only two examples of non-equational stable theories are known. We construct non-equational stable theories by a suitable colouring of the free pseudospace, based on Hrushovski and Srour's original example.