一〇二上乳膠測試-2013.09.08

\[ \xymatrix{ U \ar@/_/[ddr]_y \ar@/^/[drr]^x \ar@{.>}[dr]|-{(x,y)} \\ & X \times_Z Y \ar[d]^q \ar[r]_p & X \ar[d]_f \\ & Y \ar[r]^g & Z } \]

\[ \xymatrix{ A &*+[F]{\sum_{i=n}^m {i^2}} \\ & {\bullet} & D \ar[ul] } \]

$\xymatrix@1{ A\times B\times C\times D \ar[r]^-{+} &B }$

\[ \xymatrix{ \ar @{} [dr] |{=} A \ar[d] \ar[r] & B \ar[d] \\ B \ar[r] & C } \]

\[ \xymatrix{ A \ar@ [dr]^a_{.} \\ & B \ar@ [ul]^b \ar@ [r]^c & C \ar@ [l]^d_{.} } \]

\[ \xymatrix{ {\circ} \ar@{|-->} ’[dr] ^a ’[rr]+D*{\bullet} ^b [drrr] ^c & {\circ} & {\circ} & {\circ} \\ {\circ} & {\circ} & {\circ} & {\circ} } \]