text/appendixes/comparing_defs.tex
changeset 969 2232d94b90b8
parent 967 6e4f0ed47e0e
child 970 7f47bf84b0f1
equal deleted inserted replaced
968:8372e04e4b7d 969:2232d94b90b8
   215 rely heavily on the extended isotopy invariance of 2-morphisms in $\cC$.
   215 rely heavily on the extended isotopy invariance of 2-morphisms in $\cC$.
   216 Extended isotopy invariance implies that adding a product collar to a 2-morphism of $\cC$ has no effect,
   216 Extended isotopy invariance implies that adding a product collar to a 2-morphism of $\cC$ has no effect,
   217 and by cutting and regluing we can insert (or delete) product regions in the interior of 2-morphisms as well.
   217 and by cutting and regluing we can insert (or delete) product regions in the interior of 2-morphisms as well.
   218 Figure \ref{fig:product-regions} shows some examples.
   218 Figure \ref{fig:product-regions} shows some examples.
   219 \begin{figure}[t]
   219 \begin{figure}[t]
   220 $$
   220 %$$
   221 \mathfig{0.5}{triangle/triangle2}
   221 %\mathfig{0.5}{triangle/triangle2}
   222 $$
   222 %$$
   223 \begin{align*}
   223 \begin{align*}
   224 \begin{tikzpicture}[baseline]
   224 \begin{tikzpicture}[baseline]
   225 \node[draw] (c) at (0,0) [circle through = {(1,0)}] {$f$};
   225 \node[draw] (c) at (0,0) [circle through = {(1,0)}] {$f$};
   226 \node (d) at (c.east) [circle through = {(0.25,0)}] {};
   226 \node (d) at (c.east) [circle through = {(0.25,0)}] {};
   227 \foreach \n in {1,2} {
   227 \foreach \n in {1,2} {
   761 \end{align*}
   761 \end{align*}
   762 \caption{Horizontal composition of 2-morphisms}
   762 \caption{Horizontal composition of 2-morphisms}
   763 \label{fzo5}
   763 \label{fzo5}
   764 \end{figure}
   764 \end{figure}
   765 \begin{figure}[t]
   765 \begin{figure}[t]
   766 $$
   766 %$$
   767 \mathfig{0.6}{triangle/triangle3c}
   767 %\mathfig{0.6}{triangle/triangle3c}
   768 $$
   768 %$$
   769 $$
   769 $$
   770 \begin{tikzpicture}
   770 \begin{tikzpicture}
   771 \node (fg1) at (0,0) {
   771 \node (fg1) at (0,0) {
   772 \begin{tikzpicture}[baseline=-0.6cm]
   772 \begin{tikzpicture}[baseline=-0.6cm]
   773 \path (0,0) coordinate (f1);
   773 \path (0,0) coordinate (f1);
   781 \draw (f1) .. controls +(1,-1) and +(-1,-.4) .. (g1);
   781 \draw (f1) .. controls +(1,-1) and +(-1,-.4) .. (g1);
   782 \draw (g1) .. controls +(1,-.8) and +(-1,-.8) .. (g2);
   782 \draw (g1) .. controls +(1,-.8) and +(-1,-.8) .. (g2);
   783 \draw[dashed] (g1) .. controls +(1,.4) and +(-1,.4) .. (g2);
   783 \draw[dashed] (g1) .. controls +(1,.4) and +(-1,.4) .. (g2);
   784 \draw (f2) .. controls +(1,.4) and +(-1,1) .. (g2);
   784 \draw (f2) .. controls +(1,.4) and +(-1,1) .. (g2);
   785 %
   785 %
   786 \draw[blue,->] (-0.8,-1.2) node[below] {$(a \circ d) \times I$} -- (1,-0.5) ;
   786 \draw[blue,->] (-0.8,-1.2) node[below] {$(a \bullet d) \times I$} -- (1,-0.5) ;
   787 \path[clip] (f1) .. controls +(1,-.4) and +(-1,-.4) .. (f2)
   787 \path[clip] (f1) .. controls +(1,-.4) and +(-1,-.4) .. (f2)
   788                     .. controls +(1,.4) and +(-1,1) .. (g2)
   788                     .. controls +(1,.4) and +(-1,1) .. (g2)
   789                     .. controls +(-1,.4) and +(1,.4) .. (g1)
   789                     .. controls +(-1,.4) and +(1,.4) .. (g1)
   790                     .. controls +(-1,-.4) and +(1,-1) .. (f1);
   790                     .. controls +(-1,-.4) and +(1,-1) .. (f1);
   791 \foreach \x in {0,0.1, ..., 6} {
   791 \foreach \x in {0,0.1, ..., 6} {
   840 \draw (f1) .. controls +(1,-.8) and +(-1,-.8) .. (f2);
   840 \draw (f1) .. controls +(1,-.8) and +(-1,-.8) .. (f2);
   841 \draw (g1) .. controls +(1,-.8) and +(-1,-.8) .. (g2);
   841 \draw (g1) .. controls +(1,-.8) and +(-1,-.8) .. (g2);
   842 \draw[dashed] (g1) .. controls +(1,.8) and +(-1,.8) .. (g2);
   842 \draw[dashed] (g1) .. controls +(1,.8) and +(-1,.8) .. (g2);
   843 \draw (f1) .. controls +(1,1.5) and +(-1,1.5)..(g2);
   843 \draw (f1) .. controls +(1,1.5) and +(-1,1.5)..(g2);
   844 %
   844 %
   845 \draw[blue,->] (4,1.75) node[above] {$(b \circ d) \times I$}-- + (0,-1);
   845 \draw[blue,->] (4,1.75) node[above] {$(b \bullet d) \times I$}-- + (0,-1);
   846 \begin{scope}
   846 \begin{scope}
   847 \path[clip] (f1) ..  controls +(1,1.5) and +(-1,1.5).. (g2)
   847 \path[clip] (f1) ..  controls +(1,1.5) and +(-1,1.5).. (g2)
   848 		      .. controls +(-1,.8) and +(1,.8) .. (f2)
   848 		      .. controls +(-1,.8) and +(1,.8) .. (f2)
   849 		      .. controls +(-1,.8) and + (1,.8) .. (f1);
   849 		      .. controls +(-1,.8) and + (1,.8) .. (f1);
   850 \foreach \x in {0,0.1, ..., 6} {
   850 \foreach \x in {0,0.1, ..., 6} {
   851 	\draw[green!50!brown] (\x,-2) -- + (0,4);
   851 	\draw[green!50!brown] (\x,-2) -- + (0,4);
   852 }
   852 }
   853 \end{scope}
   853 \end{scope}
   854 \end{tikzpicture}
   854 \end{tikzpicture}
   855 };
   855 };
   856 \draw[->] ($(fg1.south)+(0,0.5)$) -- node[left=0.5cm] {add $(b \circ d) \times I$} (fg2);
   856 \draw[->] ($(fg1.south)+(0,0.5)$) -- node[left=0.5cm] {add $(b \bullet d) \times I$} (fg2);
   857 \draw[->] (fg2) -- node[right=0.5cm] {remove $(a \circ d) \times I$} ($(fg3.south)+(0,1.75)$);
   857 \draw[->] (fg2) -- node[right=0.5cm] {remove $(a \bullet d) \times I$} ($(fg3.south)+(0,1.75)$);
   858 \path (fg1) -- node {$=$} (fg3);
   858 \path (fg1) -- node {$=$} (fg3);
   859 \end{tikzpicture}
   859 \end{tikzpicture}
   860 $$
   860 $$
   861 \caption{Part of the proof that the four different horizontal compositions of 2-morphisms are equal.}
   861 \caption{Part of the proof that the four different horizontal compositions of 2-morphisms are equal.}
   862 \label{fig:horizontal-compositions-equal}
   862 \label{fig:horizontal-compositions-equal}
   864 
   864 
   865 Given 1-morphisms $a$, $b$ and $c$ of $D$, we define the associator from $(a\bullet b)\bullet c$ to $a\bullet(b\bullet c)$
   865 Given 1-morphisms $a$, $b$ and $c$ of $D$, we define the associator from $(a\bullet b)\bullet c$ to $a\bullet(b\bullet c)$
   866 as in Figure \ref{fig:associator}.
   866 as in Figure \ref{fig:associator}.
   867 This is just a reparameterization of the pinched product $(a\bullet b\bullet c)\times I$ of $\cC$.
   867 This is just a reparameterization of the pinched product $(a\bullet b\bullet c)\times I$ of $\cC$.
   868 \begin{figure}[t]
   868 \begin{figure}[t]
   869 $$
   869 %$$
   870 \mathfig{0.4}{triangle/triangle4a}
   870 %\mathfig{0.4}{triangle/triangle4a}
   871 $$
   871 %$$
   872 $$
   872 $$
   873 \begin{tikzpicture}
   873 \begin{tikzpicture}
   874 \node[circle,fill=black,inner sep=1pt] at (1.73,0) {};
   874 \node[circle,fill=black,inner sep=1pt] at (1.73,0) {};
   875 \node[circle,fill=black,inner sep=1pt] at (-1.73,0) {};
   875 \node[circle,fill=black,inner sep=1pt] at (-1.73,0) {};
   876 \begin{scope}[yshift=-1cm]
   876 \begin{scope}[yshift=-1cm]
   927 (See also Figures \ref{fzo2} and \ref{fig:associator}.)
   927 (See also Figures \ref{fzo2} and \ref{fig:associator}.)
   928 We now show that $D$ satisfies the triangle axiom, which states that $u\bullet\id_b$ 
   928 We now show that $D$ satisfies the triangle axiom, which states that $u\bullet\id_b$ 
   929 is equal to the composition of $\alpha$ and $\id_a\bullet v$.
   929 is equal to the composition of $\alpha$ and $\id_a\bullet v$.
   930 (Both are 2-morphisms from $(a\bullet \id_y)\bullet b$ to $a\bullet b$.)
   930 (Both are 2-morphisms from $(a\bullet \id_y)\bullet b$ to $a\bullet b$.)
   931 \begin{figure}[t]
   931 \begin{figure}[t]
   932 \begin{align*}
   932 %\begin{align*}
   933 \mathfig{0.4}{triangle/triangle4a} \\
   933 %\mathfig{0.4}{triangle/triangle4a} \\
   934 \mathfig{0.4}{triangle/triangle4b} \\
   934 %\mathfig{0.4}{triangle/triangle4b} \\
   935 \mathfig{0.4}{triangle/triangle4c}
   935 %\mathfig{0.4}{triangle/triangle4c}
   936 \end{align*}
   936 %\end{align*}
   937 \begin{align*}
   937 \begin{align*}
   938 \alpha & = 
   938 \alpha & = 
   939 \begin{tikzpicture}[baseline]
   939 \begin{tikzpicture}[baseline]
   940 \node[circle,fill=black,inner sep=1pt] at (1.73,0) {};
   940 \node[circle,fill=black,inner sep=1pt] at (1.73,0) {};
   941 \node[circle,fill=black,inner sep=1pt] at (-1.73,0) {};
   941 \node[circle,fill=black,inner sep=1pt] at (-1.73,0) {};
  1010 	\path (R) to[out=0,in=-140] node[pos=\x/10] (RQ\x) {} (Q);
  1010 	\path (R) to[out=0,in=-140] node[pos=\x/10] (RQ\x) {} (Q);
  1011 	\draw[brown] (PQ\x.center) -- (RQ\x.center);
  1011 	\draw[brown] (PQ\x.center) -- (RQ\x.center);
  1012 }
  1012 }
  1013 \end{tikzpicture} \\
  1013 \end{tikzpicture} \\
  1014 \end{align*}
  1014 \end{align*}
  1015 \nn{remember to change `assoc' to $\alpha$}
       
  1016 \caption{Ingredients for the triangle axiom.}
  1015 \caption{Ingredients for the triangle axiom.}
  1017 \label{fig:ingredients-triangle-axiom}
  1016 \label{fig:ingredients-triangle-axiom}
  1018 \end{figure}
  1017 \end{figure}
  1019 
  1018 
  1020 The horizontal compositions $u\bullet\id_b$ and $\id_a\bullet v$ are shown in Figure \ref{fig:horizontal-composition}
  1019 The horizontal compositions $u\bullet\id_b$ and $\id_a\bullet v$ are shown in Figure \ref{fig:horizontal-composition}
  1023 Figure \ref{fig:adding-a-collar} shows that we can add a collar to $u\bullet\id_b$ so that the result differs from
  1022 Figure \ref{fig:adding-a-collar} shows that we can add a collar to $u\bullet\id_b$ so that the result differs from
  1024 Figure  \ref{fig:vertical-composition} by an isotopy rel boundary.
  1023 Figure  \ref{fig:vertical-composition} by an isotopy rel boundary.
  1025 Note that here we have used in an essential way the associativity of product morphisms (Axiom \ref{axiom:product}.3) 
  1024 Note that here we have used in an essential way the associativity of product morphisms (Axiom \ref{axiom:product}.3) 
  1026 as well as compatibility of product morphisms with fiber-preserving maps (Axiom \ref{axiom:product}.1).
  1025 as well as compatibility of product morphisms with fiber-preserving maps (Axiom \ref{axiom:product}.1).
  1027 \begin{figure}[t]
  1026 \begin{figure}[t]
       
  1027 %\begin{align*}
       
  1028 %\mathfig{0.4}{triangle/triangle4d}
       
  1029 %\mathfig{0.4}{triangle/triangle4e} \\
       
  1030 %\end{align*}
  1028 \begin{align*}
  1031 \begin{align*}
  1029 \mathfig{0.4}{triangle/triangle4d}
  1032 u *_h (b \times I) & = 
  1030 \mathfig{0.4}{triangle/triangle4e} \\
       
  1031 \end{align*}
       
  1032 \begin{align*}
       
  1033 u \bullet (b \times I) & = 
       
  1034 \begin{tikzpicture}[baseline]
  1033 \begin{tikzpicture}[baseline]
  1035 \coordinate (L) at (0,0);
  1034 \coordinate (L) at (0,0);
  1036 \coordinate (R) at (3,0);
  1035 \coordinate (R) at (3,0);
  1037 \coordinate (T) at (1.5,0.8);
  1036 \coordinate (T) at (1.5,0.8);
  1038 \coordinate (M) at (1.5,-0.4);
  1037 \coordinate (M) at (1.5,-0.4);
  1056 	\path (M) to[out=-20,in=-150] node[coordinate,pos=\n/8] (MR\n) {} (R);
  1055 	\path (M) to[out=-20,in=-150] node[coordinate,pos=\n/8] (MR\n) {} (R);
  1057 	\path (T) to[out=0,in=140] node[coordinate,pos=\n/8] (TR\n) {} (R);
  1056 	\path (T) to[out=0,in=140] node[coordinate,pos=\n/8] (TR\n) {} (R);
  1058 	\draw[brown] (MR\n) -- (TR\n);
  1057 	\draw[brown] (MR\n) -- (TR\n);
  1059 }
  1058 }
  1060 \end{tikzpicture} \\
  1059 \end{tikzpicture} \\
  1061 (a \times I) \bullet v & = 
  1060 (a \times I) *_h v & = 
  1062 \begin{tikzpicture}[baseline]
  1061 \begin{tikzpicture}[baseline]
  1063 \coordinate (L) at (0,0);
  1062 \coordinate (L) at (0,0);
  1064 \coordinate (R) at (3,0);
  1063 \coordinate (R) at (3,0);
  1065 \coordinate (T) at (1.5,0.8);
  1064 \coordinate (T) at (1.5,0.8);
  1066 \coordinate (M) at (1.5,-0.4);
  1065 \coordinate (M) at (1.5,-0.4);
  1090 \caption{Horizontal compositions in the triangle axiom.}
  1089 \caption{Horizontal compositions in the triangle axiom.}
  1091 \label{fig:horizontal-composition}
  1090 \label{fig:horizontal-composition}
  1092 \end{figure}
  1091 \end{figure}
  1093 \begin{figure}[t]
  1092 \begin{figure}[t]
  1094 \begin{align*}
  1093 \begin{align*}
  1095 \mathfig{0.4}{triangle/triangle4f} \\
  1094 %\mathfig{0.4}{triangle/triangle4f} \\
  1096 \begin{tikzpicture}
  1095 \begin{tikzpicture}
  1097 \node[circle,fill=black,inner sep=1pt] (A) at (1.73,0) {};
  1096 \node[circle,fill=black,inner sep=1pt] (A) at (1.73,0) {};
  1098 \node[circle,fill=black,inner sep=1pt] (B) at (-1.73,0) {};
  1097 \node[circle,fill=black,inner sep=1pt] (B) at (-1.73,0) {};
  1099 \draw[dashed] (A) -- (B);
  1098 \draw[dashed] (A) -- (B);
  1100 \node[circle,fill=black,inner sep=1pt] (C) at (0,0) {};
  1099 \node[circle,fill=black,inner sep=1pt] (C) at (0,0) {};
  1145 \end{align*}
  1144 \end{align*}
  1146 \caption{Vertical composition in the triangle axiom.}
  1145 \caption{Vertical composition in the triangle axiom.}
  1147 \label{fig:vertical-composition}
  1146 \label{fig:vertical-composition}
  1148 \end{figure}
  1147 \end{figure}
  1149 \begin{figure}[t]
  1148 \begin{figure}[t]
  1150 \begin{align*}
  1149 %\begin{align*}
  1151 \mathfig{0.4}{triangle/triangle5}
  1150 %\mathfig{0.4}{triangle/triangle5}
  1152 \end{align*}
  1151 %\end{align*}
  1153 \begin{align*}
  1152 \begin{align*}
  1154 \begin{tikzpicture}[baseline]
  1153 \begin{tikzpicture}[baseline]
  1155 \coordinate (L) at (0,0);
  1154 \coordinate (L) at (0,0);
  1156 \coordinate (R) at (3,0);
  1155 \coordinate (R) at (3,0);
  1157 \coordinate (T) at (1.5,0.8);
  1156 \coordinate (T) at (1.5,0.8);