# HG changeset patch # User Scott Morrison # Date 1300919438 25200 # Node ID 58c9e149d05a7598c3d5a7b145d387fea0bc994b # Parent 0ec80a7773dcef7e4464c50481aee22ba6dd2048# Parent a53b3dd7ea9fc7fb492512a09aae13ad6c0fdfeb Automated merge with http://tqft.net/hg/blob diff -r 0ec80a7773dc -r 58c9e149d05a text/appendixes/comparing_defs.tex --- a/text/appendixes/comparing_defs.tex Wed Mar 23 15:29:31 2011 -0700 +++ b/text/appendixes/comparing_defs.tex Wed Mar 23 15:30:38 2011 -0700 @@ -118,12 +118,12 @@ Each approach has advantages and disadvantages. For better or worse, we choose bigons here. -Define the $k$-morphisms $C^k$ of $C$ to be $\cC(B^k)_E$, where $B^k$ denotes the standard +Define the $k$-morphisms $C^k$ of $C$ to be $\cC(B^k) \trans E$, where $B^k$ denotes the standard $k$-ball, which we also think of as the standard bihedron (a.k.a.\ globe). (For $k=1$ this is an interval, and for $k=2$ it is a bigon.) Since we are thinking of $B^k$ as a bihedron, we have a standard decomposition of the $\bd B^k$ into two copies of $B^{k-1}$ which intersect along the ``equator" $E \cong S^{k-2}$. -Recall that the subscript in $\cC(B^k)_E$ means that we consider the subset of $\cC(B^k)$ +Recall that the subscript in $\cC(B^k) \trans E$ means that we consider the subset of $\cC(B^k)$ whose boundary is splittable along $E$. This allows us to define the domain and range of morphisms of $C$ using boundary and restriction maps of $\cC$. diff -r 0ec80a7773dc -r 58c9e149d05a text/ncat.tex --- a/text/ncat.tex Wed Mar 23 15:29:31 2011 -0700 +++ b/text/ncat.tex Wed Mar 23 15:30:38 2011 -0700 @@ -207,16 +207,16 @@ We do not insist on surjectivity of the gluing map, since this is not satisfied by all of the examples we are trying to axiomatize. -If our $k$-morphisms $\cC(X)$ are labeled cell complexes embedded in $X$, then a $k$-morphism is +If our $k$-morphisms $\cC(X)$ are labeled cell complexes embedded in $X$ (c.f. Example \ref{ex:traditional-n-categories} below), then a $k$-morphism is in the image of the gluing map precisely which the cell complex is in general position -with respect to $E$. +with respect to $E$. On the other hand, in categories based on maps to a target space (c.f. Example \ref{ex:maps-to-a-space} below) the gluing map is always surjective If $S$ is a 0-sphere (the case $k=1$ above), then $S$ can be identified with the {\it disjoint} union of two 0-balls $B_1$ and $B_2$ and the colimit construction $\cl{\cC}(S)$ can be identified with the (ordinary, not fibered) product $\cC(B_1) \times \cC(B_2)$. Let $\cl{\cC}(S)\trans E$ denote the image of $\gl_E$. -We will refer to elements of $\cl{\cC}(S)\trans E$ as ``splittable along $E$" or ``transverse to $E$". +We will refer to elements of $\cl{\cC}(S)\trans E$ as ``splittable along $E$" or ``transverse to $E$". When the gluing map is surjective every such element is splittable. If $X$ is a $k$-ball and $E \sub \bd X$ splits $\bd X$ into two $k{-}1$-balls $B_1$ and $B_2$ as above, then we define $\cC(X)\trans E = \bd^{-1}(\cl{\cC}(\bd X)\trans E)$.