Here are some examples of active and inert maps of pointed sets.

  1. The map $\mu \colon \left\langle 2\right\rangle \to \left\langle 1\right\rangle $ given by

    is active but not inert.

  2. The map $f\colon \left\langle 2\right\rangle \to \left\langle 2\right\rangle $ given by

    is inert but not active.

  3. The map $f\colon \left\langle 3\right\rangle \to \left\langle 1\right\rangle $ given by

    is neither inert nor active. However, it factors as $f=a\circ i$, where

    \begin{align*} i & \colon \left\langle 3\right\rangle \to \left\langle 2\right\rangle ,\\ a & \colon \left\langle 2\right\rangle \to \left\langle 1\right\rangle \end{align*}

    are the morphisms of pointed sets given by

    with $i$ being inert and $a$ being active.


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


You can also use the contact form below: