summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorGregor Kleen <gkleen@yggdrasil.li>2016-02-03 21:33:46 +0100
committerGregor Kleen <gkleen@yggdrasil.li>2016-02-03 21:33:46 +0100
commit7f1293b7afa7574d93c07fd34dc472bb0979a98f (patch)
tree98bf670814465c36337f50c1e46206770cafed47
parent927fe04b9bc95239bc6e6506e74bd47d6edbe0b0 (diff)
downloaddirty-haskell.org-7f1293b7afa7574d93c07fd34dc472bb0979a98f.tar
dirty-haskell.org-7f1293b7afa7574d93c07fd34dc472bb0979a98f.tar.gz
dirty-haskell.org-7f1293b7afa7574d93c07fd34dc472bb0979a98f.tar.bz2
dirty-haskell.org-7f1293b7afa7574d93c07fd34dc472bb0979a98f.tar.xz
dirty-haskell.org-7f1293b7afa7574d93c07fd34dc472bb0979a98f.zip
minor corrections
-rw-r--r--provider/posts/simmons-intro-to-cat-t/1.2.md8
1 files changed, 4 insertions, 4 deletions
diff --git a/provider/posts/simmons-intro-to-cat-t/1.2.md b/provider/posts/simmons-intro-to-cat-t/1.2.md
index e180c6d..faaf429 100644
--- a/provider/posts/simmons-intro-to-cat-t/1.2.md
+++ b/provider/posts/simmons-intro-to-cat-t/1.2.md
@@ -14,7 +14,7 @@ Let $\ca{Pno}$ be the category of objects $(A, \alpha, a)$ where $A$ is a set, $
14 $\id$ on $A$ is indeed a function which preserves the structure ($\id \circ \alpha = \alpha = \alpha \circ \id$, $\id(a) = a$) and thus a morphism 14 $\id$ on $A$ is indeed a function which preserves the structure ($\id \circ \alpha = \alpha = \alpha \circ \id$, $\id(a) = a$) and thus a morphism
15 </div> 15 </div>
16 16
17 2. There exists a partial binary operation $\circ$ on the arrows of $\ca{Pno}$ 17 2. There exists an associative partial binary operation $\circ$ on the arrows of $\ca{Pno}$
18 <div class="proof"> 18 <div class="proof">
19 Given three objects $(A, \alpha, a), (B, \beta, b), (C, \gamma, c)$ and two functions $g: A \to B$ and $f: B \to C$ the function $f \circ g: A \to C$ is an arrow in $\ca{Pno}$, that is to say, it preserves structure: 19 Given three objects $(A, \alpha, a), (B, \beta, b), (C, \gamma, c)$ and two functions $g: A \to B$ and $f: B \to C$ the function $f \circ g: A \to C$ is an arrow in $\ca{Pno}$, that is to say, it preserves structure:
20 $$(f \circ g) \circ \alpha = f \circ \beta \circ g = \gamma \circ (f \circ g)$$ 20 $$(f \circ g) \circ \alpha = f \circ \beta \circ g = \gamma \circ (f \circ g)$$
@@ -62,7 +62,7 @@ Show that such objects and morphisms form a category $\ca{SetD}$
62 $\id$ on $A$ is indeed a function which respects the distinguished subset ($\forall \alpha \in a \ldotp \id(\alpha) \in a$) and thus a morphism 62 $\id$ on $A$ is indeed a function which respects the distinguished subset ($\forall \alpha \in a \ldotp \id(\alpha) \in a$) and thus a morphism
63 </div> 63 </div>
64 64
65 2. There exists a partial binary operation $\circ$ on the arrows of $\ca{SetD}$ 65 2. There exists an associative partial binary operation $\circ$ on the arrows of $\ca{SetD}$
66 <div class="proof"> 66 <div class="proof">
67 Given three objects $(A, a), (B, b), (C, c)$ and two functions $g: A \to B$ and $f: B \to C$ the function $f \circ g: A \to C$ is an arrow in $\ca{SetD}$, that is to say, $\forall \alpha \in a$: 67 Given three objects $(A, a), (B, b), (C, c)$ and two functions $g: A \to B$ and $f: B \to C$ the function $f \circ g: A \to C$ is an arrow in $\ca{SetD}$, that is to say, $\forall \alpha \in a$:
68 $$(f \circ g)(\alpha) = f(b) = c$$ 68 $$(f \circ g)(\alpha) = f(b) = c$$
@@ -83,7 +83,7 @@ We call the category comprised of such objects and arrows $\ca{RelH}$.
83 83
84 $\id$ on $A$ is indeed a function which respects the binary relation ($\forall a \odot a^\prime \ldotp \id(a) \odot \id(a^\prime)$) and thus a morphism 84 $\id$ on $A$ is indeed a function which respects the binary relation ($\forall a \odot a^\prime \ldotp \id(a) \odot \id(a^\prime)$) and thus a morphism
85 85
86 2. There exists a partial binary operation $\circ$ on the arrows of $\ca{RelH}$ 86 2. There exists an associative partial binary operation $\circ$ on the arrows of $\ca{RelH}$
87 87
88 Given three objects $(A, \odot), (B, \oplus), (C, \otimes)$ and two functions $g: A \to B$ and $f: B \to C$ the function $f \circ g: A \to C$ is an arrow in $\ca{RelH}$, that is to say, $\forall a \odot a^\prime$: 88 Given three objects $(A, \odot), (B, \oplus), (C, \otimes)$ and two functions $g: A \to B$ and $f: B \to C$ the function $f \circ g: A \to C$ is an arrow in $\ca{RelH}$, that is to say, $\forall a \odot a^\prime$:
89 $$a \odot a^\prime \implies g(a) \oplus g(a^\prime) \implies (g \circ f)(a) \otimes (g \circ f)(a^\prime)$$ 89 $$a \odot a^\prime \implies g(a) \oplus g(a^\prime) \implies (g \circ f)(a) \otimes (g \circ f)(a^\prime)$$
@@ -98,7 +98,7 @@ Topological spaces $(S, \mathcal{O}_S)$, where $S$ is a Set and $\mathcal{O}_S \
98 $\id$ on $S$ is indeed a continuous map and thus a morphism 98 $\id$ on $S$ is indeed a continuous map and thus a morphism
99 </div> 99 </div>
100 100
101 2. There exists a partial binary operation $\circ$ on the arrows of $\ca{Top}$ 101 2. There exists an associative partial binary operation $\circ$ on the arrows of $\ca{Top}$
102 <div class="proof"> 102 <div class="proof">
103 Given three spaces $(S, \mathcal{O}_S), (T, \mathcal{O}_T), (U, \mathcal{O}_U)$ and two continuous maps $g : S \to T$ and $f : T \to U$ the map $f \circ g : S \to U$ is an arrow in $\ca{Top}$, that is to say, it is contiuous: 103 Given three spaces $(S, \mathcal{O}_S), (T, \mathcal{O}_T), (U, \mathcal{O}_U)$ and two continuous maps $g : S \to T$ and $f : T \to U$ the map $f \circ g : S \to U$ is an arrow in $\ca{Top}$, that is to say, it is contiuous:
104 $$V \in \mathcal{O}_U \implies g^\leftarrow(V) \in \mathcal{O}_T \implies (f \circ g)^\leftarrow(V) \in \mathcal{O}_S$$ 104 $$V \in \mathcal{O}_U \implies g^\leftarrow(V) \in \mathcal{O}_T \implies (f \circ g)^\leftarrow(V) \in \mathcal{O}_S$$