4
$\begingroup$

This is a very short question.

Any consistent first order theory has a model in Set. Is it true that any consistent first order theory has a model in an elementary topos?

$\endgroup$
2
  • $\begingroup$ Do you mean to ask "is there a model of every coherent theory in every elementary topos", or are you asking if the notion of "model in an elementary topos" makes sense in the first place? $\endgroup$
    – user231101
    Commented Apr 27, 2017 at 1:52
  • $\begingroup$ I am meaning the notion at page 530 in Sheaves in Geometry and Logic. $\endgroup$ Commented Apr 27, 2017 at 7:08

1 Answer 1

2
$\begingroup$

Answer is no, FinSet has no Models for Peano Numbers.

$\endgroup$
0

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .