A theory 
Then 
We defined Rosser sentences and showed their undecidability. We also showed Löb’s theorem that if 
Finally, we showed that the length of proofs of 
A kind of library
Andrés E. Caicedo
Recent Comments
Mathoverflow- Convergence of $\sum(n^3\sin^2n)^{-1}$
- Answer by Andrés E. Caicedo for Well known theorems that have not been proved
- Answer by Andrés E. Caicedo for Where is the Erdős–Rado theorem stated in Erdős and Rado's Bull AMS paper?
- Answer by Andrés E. Caicedo for The Erdős-Turán conjecture or the Erdős' conjecture?
- Relative densities
- On the division paradox
- Answer by Andrés E. Caicedo for Relative densities
- Answer by Andrés E. Caicedo for Proof theoretic ordinal
- Answer by Andrés E. Caicedo for Projection of Borel set from $R^2$ to $R^1$
- Answer by Andrés E. Caicedo for Does Turing determinacy imply full determinacy?
- Math.StackExchange
- Answer by Andrés E. Caicedo for What is the cardinality of $A \times \mathbb N$ if $\left \lvert A \right \rvert \geq \aleph_0\ $?
- Answer by Andrés E. Caicedo for Any partition of an at most countable set has a set of representatives.
- Answer by Andrés E. Caicedo for Is the class of all sets that contain the empty set as element a proper class in ZF?
- Answer by Andrés E. Caicedo for cardinal exponentiation with lower cardinal
- Answer by Andrés E. Caicedo for $\beta > 0$ and $\alpha \cdot \beta = \beta \implies \alpha ^{\omega} \leq \beta$
- Does $|X|^m\cdot n^{|X|}\le (n+m)^{|X|}$ hold without choice?
- Answer by Andrés E. Caicedo for Transfinite derivatives
- Answer by Andrés E. Caicedo for cardinals such that $\alpha < \alpha ^ \beta$
- Answer by Andrés E. Caicedo for Prove that Baire space $\omega^\omega$ is completely metrizable?
- Answer by Andrés E. Caicedo for Is it possible for a function to be smooth everywhere, analytic nowhere, yet Taylor series at any point converges in a nonzero radius?
A kind of library 