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Conjecture on preservation of left adjoint bicomodules and a ternary factorization system by Lan{p ∘ −}{p}

Prove that the functor Lan{p ∘ −}{p} sends left adjoint bicomodules to left adjoint bicomodules and preserves the ternary factorization system (Δ_ff, Δ_bo, Σ_dopf) on left adjoint bicomodules.

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Background

The paper develops a P-enriched functorial selection-category construction S_C(p) ≅ Lan{p ∘ C}{p} and shows it respects bijective-on-objects and fully faithful morphisms, suggesting deeper structural preservation properties.

The authors conjecture that these observed properties are explained by a more fundamental preservation behavior of Lan{p ∘ −}{p} at the level of bicomodules and their factorization system, specifically the ternary factorization system (Δ_ff, Δ_bo, Σ_dopf). Establishing this would clarify the structural reasons behind the well-behavedness results proved for selection categories.

References

While it is beyond the scope of this paper, we conjecture that the considerations in this section arise because Lan{p\circ-}{p} sends left adjoint bicomodules to left adjoint bicomodules, and preserves the ternary factorization system $(\Delta_ff\Delta_bo\Sigma_dopf)$ of left adjoint bicomodules.

Categories by Kan extension (2503.21974 - Spivak, 27 Mar 2025) in Chapter 7 (Basic theory of selection categories), final paragraph