<a href="https://en.wikipedia.org/wiki/Commutative_diagram" class="extiw" title="en:Commutative diagram">en:Commutative diagram</a> for <a href="https://en.wikipedia.org/wiki/adjoint_functors" class="extiw" title="en:adjoint functors">en:adjoint functors</a>
<a href="//commons.wikimedia.org/wiki/User:TomT0m" title="User:TomT0m">TomT0m</a>
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<span class="int-own-work" lang="en">Own work</span>