Intertwining matrices for number fields: Supplement to “Intertwiners and the K-theory of commutative rings”

Since not all the matrices appearing in [A. J. Berrick, Intertwiners and the K-theory of commutative rings, J. reine angew. Math. 569 (2004), 55–101.], Proposition 10.4 are intertwining matrices as claimed, we present a corrected version here. Moreover, with only a little extra work, we then generalize the result from quadratic to arbitrary number fields.