2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/184608We show that a suitable coset algebra, constructed in terms of an extension of the Zamolodchikov-Faddeev algebra, is homomorphic to the Reflection-Transmission algebra, as it appears in the study of integrable systems with impurity.8 pages; a misprint in eq. (2.14) and (2.15) has been correctedQuantum AlgebraHigh Energy Physics - TheoryMathematical Physics17B37text