New posts in Foundations

How to construct natural numbers by set theory?

In a topos with a NNO, how does one define the subobject "$<$'' of $\mathbf N\times\mathbf N$?

How badly does foundation fail in NF(etc.)?

How do we know our definitions don't lead to contradictions

Is consistency an axiom of mathematics?

Categoricity of second order theories - precisely what does it mean?

Does the successor function imply order?

Why is Axiom of Pairing needed?

What makes radians superior to turns/revolutions?

Reference of the connection of category theory and logic(foundation of mathematics)