I'm reading Goldblatt's "Topoi: A Categorial Analysis of Logic."

There's a symbol I don't recognise on page 302 of the copy with International Standard Book Number 0-486-45026-0. It's in the definition of a natural number object and resembles a cross between $s$ and $\sigma$.

For lack of a better format to show you what it is, here is a picture:

Natural number object symbol.

I have tried using Detexify but to no avail.

What symbol is it?

Please help :)


That symbol looks like a cursive letter s (lower case).

  • 2
    $\begingroup$ From that Wikipedia article: Cursive has been in decline throughout the 21st century due to its perceived lack of necessity. The largest teachers' union in Fairfax County, Virginia, has called cursive a "dying art" $\endgroup$ – J. W. Tanner Jan 26 at 17:07
  • 1
    $\begingroup$ Your answer would make sense in the context. The motivating example for an nno talks of the successor function on the natural numbers, denoted $s$. Thank you :) $\endgroup$ – Shaun Jan 26 at 17:09

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.