• Functoriality. The assignment $U\mapsto U^{\textsf{c}}$ defines a functor
    \[ \webleft (-\webright )^{\textsf{c}}\colon \mathcal{P}\webleft (X\webright )^{\mathsf{op}}\to \mathcal{P}\webleft (X\webright ). \]

    In particular, the following statements hold for each $U,V\in \mathcal{P}\webleft (X\webright )$:

    • If $U\subset V$, then $V^{\textsf{c}}\subset U^{\textsf{c}}$.


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


You can also use the contact form below: