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Andrés E. Caicedo works on set theory. His author homepage identifies the specialization, while his teaching archive develops cardinal arithmetic and elementary embeddings.^[ref]

His cardinal-arithmetic lectures explain restrictions on elementary embeddings into transitive targets. A fixed point above the critical point can have an image that the target itself does not contain, a phenomenon proved using coding and combinatorial set theory. The example illustrates why an embedding's behavior on ordinals cannot be inferred from ordinary inclusion alone.^[ref]