Title: Equational and non-equational theories 

Abstract: 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. In joint work with M. Ziegler, we construct non-equational stable theories by a suitable colouring of the free pseudospace, based on Hrushovski and Srour's original example.