³⁰To non-theorists, this notation may be slightly confusing; the inequality relations in (1) and (3) are taken to mean ‘for any speciﬁc element $∙$ in the domain of the functions in question’ so that, e.g., $x ≤ y$ is short for $x(∙) ≤ y(∙) ∀ ∙ ∈ 𝒜.$ In this notation, $ζα г$ in (3) is a function which can be applied to any argument $∙$ (because $г$ is a function).