Limit Laws and Automorphism Groups of Nonrigid Structures

Ove Ahlman and Vera Koponen

The first sentence of the introduction reads as follows.

"[...] it has been shown that for any finite relational vocabulary (also called signature), the proportion of labelled n-element structures which are rigid, ie have no nontrivial automorphism, approaches 1 as n approaches infinity"

While their paper is about nonrigid structures, here we show that there exists a rigid 2-element structure, namely Fin 2 under addition.