• Functoriality. The assignment $R\mapsto R^{\dagger }$ defines a functor (i.e. morphism of posets)
    \[ \webleft (-\webright )^{\dagger }\colon \mathbf{Rel}\webleft (A,B\webright )\to \mathbf{Rel}\webleft (B,A\webright ). \]

    In particular, given relations $R,S\colon A\mathrel {\rightrightarrows \kern -9.5pt\mathrlap {|}\kern 6pt}B$, we have:

    • If $R\subset S$, then $R^{\dagger }\subset S^{\dagger }$.


Noticed something off, or have any comments? Feel free to reach out!


You can also use the contact form below: