If the parameters are μ, κ, φ, ω, η, β = p, then no, I am not interested in that. I would like to know how many phages = Vp = u[3] I need to add and at what time point Tp in b1. As you can see in the other post (of which the present post is, ideally, a more focused continuation) there is an amount of phage = u[3] that collapses u[1]. As you suggested, how do I train DiffEqFlux to use u[3] as such a parameter? and how do I tell DiffEqFlux to take into account also the time? Thanks