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11 changes: 5 additions & 6 deletions src/content/3.14/lawvere-theories.tex
Original file line number Diff line number Diff line change
Expand Up @@ -158,8 +158,7 @@ \section{Lawvere Theories}
the category, they turn out to be products of simpler morphisms of the
type $n \to 1$. This is a generalization of the
statement that a function that returns a product is a product of
functions (or, as we've seen earlier, that the hom-functor is
continuous).
functions; as we've seen earlier, the hom-functor is continuous.

\begin{figure}[H]
\centering
Expand Down Expand Up @@ -257,7 +256,7 @@ \section{Models of Lawvere Theories}
set, there are as many of these models as there are sets in
$\Set$. Moreover, every morphism in $\cat{Mod}(\Fop, \Set)$ (a
natural transformation between functors $M$ and $N$) is
uniquely determined by its component at $M 1$. Conversely, every
uniquely determined by its component at $1$. Conversely, every
function $M 1 \to N 1$ induces a natural
transformation between the two models $M$ and $N$.
Therefore $\cat{Mod}(\Fop, \Set)$ is equivalent to $\Set$.
Expand Down Expand Up @@ -369,7 +368,7 @@ \section{Lawvere Theories and Monads}
for this monad} is equivalent to the category of models.

You may recall that monad algebras define ways to evaluate expressions
that are formed using monads. A Lawvere theory defines n-ary operations
that are formed using monads. A Lawvere theory defines $n$-ary operations
that can be used to generate expressions. Models provide means to
evaluate these expressions.

Expand Down Expand Up @@ -402,7 +401,7 @@ \section{Lawvere Theories and Monads}
The category opposite to this Kleisli category,
$\cat{Kl}^\mathit{op}_{T}$, restricted to finite
sets, is the Lawvere theory in question. In particular, the hom-set
$\cat{L}(n, 1)$ that describes n-ary operations in $\cat{L}$ is given
$\cat{L}(n, 1)$ that describes $n$-ary operations in $\cat{L}$ is given
by the hom-set $\cat{Kl}_{T}(1, n)$.

It turns out that most monads that we encounter in programming are
Expand Down Expand Up @@ -565,7 +564,7 @@ \section{Lawvere Theory of Side Effects}
\src{snippet02}
We can recover the \code{Maybe} monad using the coend formula. Let's
consider what the addition of the nullary operation does to the hom-sets
$\cat{L}(n, 1)$. Besides creating a new $\cat{L}(0, 1)$ (which is
$\cat{L}(n, 1)$. Besides creating a new element in $\cat{L}(0, 1)$ (which is
absent from $\Fop$), it also adds new morphisms
to $\cat{L}(n, 1)$. These are the results of composing morphism of the
type $n \to 0$ with our $0 \to 1$.
Expand Down