Dear categorists, I have a question which is probably obvious except for me... Take a limit theory T. Add a basic sentence to this theory to obtain a theory T'. So Mod(T') is accessible, Mod(T) is locally presentable. Is Mod(T') accessibly- embedded, i.e. does Mod(T')\subset Mod(T) preserve filtered colimits for a big enough regular cardinal ? Or in other terms, what is going on when a basic axiom is added. I cannot find any answer in Adamek&Rosicky's book. Of course I ask you the question because this is my situation. In my situation T and T' are purely relational and the signature contains the same four relation symbols. The only difference between T and T' is an additional axiom which is a basic sentence. thanks in advance. pg. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]