Elementary Topoi
It has come to my attention that I ought to clarify my logo ΩN which is containing a pdf copy of my thesis even though it isn't underlined.
Ω is a subobject classifier and N is a natural number objet, i. e. objects that occur in the context of elementary topoi.
Since my return from Connecticut to Denmark in 1981 I have been using this logo, and it has been on my homepage from day one. Ω
was chosen as it is the key to understanding the intuitionistic concept of an atom that was first described in my thesis
Lattice Theoretic and Logical Aspects of Elementary Topoi, chapter 2. The natural number object symbol N was chosen because of
its role in the construction of the free monoids which initiated the ideas collected in my thesis.
Lattice Theoretic and Logical Aspects of Elementary Topoi (2. edition 2015)
Zentralblatt (Zbl 0345.18006), Review by Gavin C. Wraith