# The beginning of the `snake lemma'.
category
snake
objects
A, B, C, A', B', C', Keh, Cof.
arrows
m:A->B, e:B->C, f:A->A', g:B->B', 
h:C->C', m':A'->B', e':B'->C', k:Keh->C, 
p:A'->Cof. 
relations
g*m = m'*f, h*e = e'*g.
gml
graph [
   directed 1
   node [
      id 0
      label "A"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x -99.61618180023694
            y -0.7483400894095382
            z -0.8703043440889644
         ]
         width 15.94
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 1
      label "B"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x -2.8421709430404007E-14
            y -2.8421709430404007E-14
            z -2.0
         ]
         width 17.36
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 2
      label "C"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x 99.9509027386791
            y 0.17650709634526152
            z -1.4585555997621782
         ]
         width 18.78
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 3
      label "A'"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x -99.99517146754263
            y -101.5446710305001
            z -1.7224701321654265
         ]
         width 18.78
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 4
      label "B'"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x 0.6465409086709712
            y -100.73192691182723
            z -0.21162936251602105
         ]
         width 20.2
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 5
      label "C'"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x 99.91441830020972
            y -101.43139036191951
            z 0.43434554761287814
         ]
         width 21.619999999999997
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 6
      label "Keh"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x 100.4814676437702
            y 98.6072353738794
            z -1.6917046369309787
         ]
         width 37.239999999999995
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 7
      label "Cof"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x -99.9026179339819
            y -200.69403542522429
            z -1.430766495125539
         ]
         width 32.98
         height 27.299999999999997
         depth 20.0
      ]
      vgj [
         labelPosition "in"
         shape "Oval"
      ]
   ]
   node [
      id 8
      label "relations\ng*m = m'*f,h*e = e'*g"
      graphics [
         Image [
            Type ""
            Location ""
         ]
         center [
            x 169.9009128475589
            y -151.30030509901817
            z -113.76631829074361
         ]
         width 20.0
         height 20.0
         depth 20.0
      ]
      vgj [
         labelPosition "center"
         shape "Oval"
      ]
   ]
   edge [
      linestyle "solid"
      label "f"
      source 0
      target 3
   ]
   edge [
      linestyle "solid"
      label "e"
      source 1
      target 2
   ]
   edge [
      linestyle "solid"
      label "e'"
      source 4
      target 5
   ]
   edge [
      linestyle "solid"
      label "k"
      source 6
      target 2
   ]
   edge [
      linestyle "solid"
      label "h"
      source 2
      target 5
   ]
   edge [
      linestyle "solid"
      label "m"
      source 0
      target 1
   ]
   edge [
      linestyle "solid"
      label "m'"
      source 3
      target 4
   ]
   edge [
      linestyle "solid"
      label "g"
      source 1
      target 4
   ]
   edge [
      linestyle "solid"
      label "p"
      source 3
      target 7
   ]
]