Definition (Time consistent)
Let D:={J,Γ,T} be a dynamic team which admits a solution γ∗∈Γ. Let t>1 be an arbitrary point in T, and consider the decision problem D[t,T]β which is derived from D by setting γ[1,t−1]=β[1,t−1], for an arbitrary β[1,t−1]∈Γ[1,t−1]. Then:
- The solution γ∗∈Γ is strongly time consistent (STC) if the subpolicy γ[t,T]∗ constitutes a solution to the dynamic team D[t,T]β, this being so for every t∈T,t>1, and every permissible β[1,t−1]∈Γ[1,t−1].
- The solution γ∗∈Γ is weakly time consistent (WTC) if the subpolicy γ[t,T]∗ constitutes a solution to the dynamic team D[t,T]β when β[1,t−1]=γ[1,t−1]∗