leroy

1.1 Basics of Locales

Definition 1 \(f^*\) and \(f_*\)
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For every continuous Function \(f : X \rightarrow Y\) between topological Spaces, there exists a pair of functors \((f^*,f_*)\).

\begin{gather*} f* = f^{-1} : O(Y) \rightarrow O(X)\\ f_* : O(X) \rightarrow O(Y) := A \mapsto \bigcup _{f^*(v) \le A} v\\ \end{gather*}
Lemma 2 \(f^* \dashv f_*\)
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\(f^*\) is the right adjoint to \(f_*\)

Proof