On principal types and well-foundedness of terms in ECC. - Eitetsu Ken; Kenji Tojo; Kazuki Watanabe 003; Masaki Natori (CoRR, 2020)

On matrix rank function over bounded arithmetics. - Eitetsu Ken; Satoru Kuroda (CoRR, 2023)

On the Complexity of Interpolation by Polynomials with Non-negative Real Coefficients. - Katsuyuki Bando; Eitetsu Ken; Hirotaka Onuki (CoRR, 2024)

Ajtai's theorem for T22(R) and pebble games with backtracking. - Eitetsu Ken; Mykyta Narusevych (CoRR, 2024)

On some Σ B0-formulae generalizing counting principles over V0. - Eitetsu Ken (Arch. Math. Log., 2025)