diff --git a/src/content/3.11/kan-extensions.tex b/src/content/3.11/kan-extensions.tex index d66119500..c555a479b 100644 --- a/src/content/3.11/kan-extensions.tex +++ b/src/content/3.11/kan-extensions.tex @@ -67,7 +67,7 @@ If the Kan extension $F = Ran_{K}D$ exists, there must be a unique natural transformation $\sigma$ from $F'$ to it, such that $\varepsilon'$ factorizes through $\varepsilon$, that is: -\[\varepsilon' = \varepsilon\ .\ (\sigma \circ K)\] +\[\varepsilon' = \varepsilon \cdot (\sigma \circ K)\] Here, $\sigma \circ K$ is the horizontal composition of two natural transformations (one of them being the identity natural transformation on $K$). This transformation is then vertically composed with @@ -104,7 +104,7 @@ \section{Right Kan Extension} there is a unique natural transformation \[\sigma \Colon F' \to F\] that factorizes $\varepsilon'$: -\[\varepsilon' = \varepsilon\ .\ (\sigma \circ K)\] +\[\varepsilon' = \varepsilon \cdot (\sigma \circ K)\] This is quite a mouthful, but it can be visualized in this nice diagram: \begin{figure}[H] @@ -238,7 +238,7 @@ \section{Left Kan Extension} \noindent such that: -\[\eta' = (\sigma \circ K)\ .\ \eta\] +\[\eta' = (\sigma \circ K) \cdot \eta\] This is illustrated in the following diagram: \begin{figure}[H] @@ -263,7 +263,7 @@ \section{Left Kan Extension} As before, we can recast the one-to-one correspondence between natural transformations: -\[\eta' = (\sigma \circ K)\ .\ \eta\] +\[\eta' = (\sigma \circ K) \cdot \eta\] in terms of the adjunction: \[[\cat{A}, \cat{C}](\Lan_{K}D, F') \cong [\cat{I}, \cat{C}](D, F' \circ K)\] In other words, the left Kan extension is the left adjoint, and the diff --git a/src/content/3.12/enriched-categories.tex b/src/content/3.12/enriched-categories.tex index 264346677..d725b7f7d 100644 --- a/src/content/3.12/enriched-categories.tex +++ b/src/content/3.12/enriched-categories.tex @@ -397,7 +397,7 @@ \section{Self Enrichment} \[[b, c] \otimes ([a, b] \otimes a) \to [b, c] \otimes b\] And use the counit $\varepsilon_{b c}$ again to get to $c$. We have thus constructed a morphism: -\[\varepsilon_{b c}\ .\ (\idarrow[{[b, c]}] \otimes \varepsilon_{a b})\ .\ \alpha_{[b, c] [a, b] a}\] +\[\varepsilon_{b c} \circ (\idarrow[{[b, c]}] \otimes \varepsilon_{a b}) \circ \alpha_{[b, c] [a, b] a}\] that is an element of the hom-set: \[\cat{V}(([b, c] \otimes [a, b]) \otimes a, c)\] The adjunction will give us the composition law we were looking for. diff --git a/src/content/3.13/topoi.tex b/src/content/3.13/topoi.tex index 0f29ace75..4f9720fdc 100644 --- a/src/content/3.13/topoi.tex +++ b/src/content/3.13/topoi.tex @@ -58,7 +58,7 @@ \section{Subobject Classifier} are equivalent if there is an isomorphism: \[h \Colon a \to a'\] such that: -\[f = f'\ .\ h\] +\[f = f' \circ h\] Such a family of equivalent injections defines a subset of $b$. \begin{figure}[H] @@ -76,7 +76,7 @@ \section{Subobject Classifier} g' & \Colon c \to a \end{align*} such that: -\[m\ .\ g = m\ .\ g'\] +\[m \circ g = m \circ g'\] it must be that $g = g'$. \begin{figure}[H] @@ -142,8 +142,8 @@ \section{Subobject Classifier} \noindent Let's analyze this diagram. The pullback equation is: -\[\mathit{true}\ .\ \mathit{unit} = \chi\ .\ f\] -The function $\mathit{true}\ .\ \mathit{unit}$ maps every element of $a$ to +\[\mathit{true} \circ \mathit{unit} = \chi \circ f\] +The function $\mathit{true} \circ \mathit{unit}$ maps every element of $a$ to ``true.'' Therefore $f$ must map all elements of $a$ to those elements of $b$ for which $\chi$ is ``true.'' These are, by definition, the elements of the subset that is specified by the