Suppose α is a feature or an X° category, and CH is the chain (α, “t”) or the trivial chain α. Then […] The “minimal domain” Min (δ(CH)) of CH is the smallest subset K of δ(CH) such that for any γ ∈ δ(CH), some β ∈ K reflexively dominates γ. - Chomsky (1995), a pag.299