“…While before the crisis, the curves were independent of δ, after the crisis the tenure can no longer be neglected. The authors of Fontana et al (2020) showed that forward-rate agreements can be decomposed into δ-bonds, which we denote by P(t, T, δ). If δ = 0 we write P(t, T) = P(t, T, 0), which is the single-curve case considered previously.…”