I am a retired high school math teacher. I have a degree in pure mathematics (1982). My dissertation was about *Semigroups of Linear Operators in Banach Spaces*.

I quitted further specialization because I liked very much teaching; anyway I love to practice math at any level.

I like very much this site, *mathexchange*, often it's too difficult for me; nevertheless it's always stimulating for me to (re)learn math topics.