diff --git a/doc/images/bipartite_matching.eps b/doc/images/bipartite_matching.eps
new file mode 100644
--- /dev/null
+++ b/doc/images/bipartite_matching.eps
@@ -0,0 +1,586 @@
+%!PS-Adobe-3.0 EPSF-3.0
+%%BoundingBox: 15 18 829 570
+%%HiResBoundingBox: 15.1913 18.4493 828.078 569.438
+%%Creator: Karbon14 EPS Exportfilter 0.5
+%%CreationDate: (04/15/06 15:20:26)
+%%For: (Balazs Dezso) ()
+%%Title: ()
+
+/N {newpath} def
+/C {closepath} def
+/m {moveto} def
+/c {curveto} def
+/l {lineto} def
+/s {stroke} def
+/f {fill} def
+/w {setlinewidth} def
+/d {setdash} def
+/r {setrgbcolor} def
+/S {gsave} def
+/R {grestore} def
+
+N
+251.402 32.047 m
+532.945 293.946 814.484 555.844 814.484 555.844 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+749.012 32.047 m
+742.465 293.946 735.918 555.844 735.918 555.844 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+539.492 32.047 m
+637.703 293.946 735.918 555.844 735.918 555.844 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+172.832 32.047 m
+454.375 293.946 735.918 555.844 735.918 555.844 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+107.355 32.047 m
+421.637 293.946 735.918 555.844 735.918 555.844 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+644.25 555.844 m
+696.633 293.946 749.012 32.047 749.012 32.047 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+474.016 555.844 m
+611.516 293.946 749.012 32.047 749.012 32.047 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+683.535 32.047 m
+663.894 293.946 644.25 555.844 644.25 555.844 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+120.453 555.844 m
+401.992 293.946 683.535 32.047 683.535 32.047 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+28.7853 555.844 m
+356.16 293.946 683.535 32.047 683.535 32.047 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+539.492 32.047 m
+546.039 293.946 552.586 555.844 552.586 555.844 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+316.875 32.047 m
+349.613 293.946 382.351 555.844 382.351 555.844 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+107.355 32.047 m
+244.855 293.946 382.351 555.844 382.351 555.844 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+290.687 555.844 m
+375.805 293.946 460.922 32.047 460.922 32.047 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+120.453 555.844 m
+290.687 293.946 460.922 32.047 460.922 32.047 c
+[] 0 d 0 0 0 r 1.96407 w s
+
+N
+172.832 32.047 m
+146.64 293.946 120.453 555.844 120.453 555.844 c
+[] 0 d 1 0 0 r 3.92814 w s
+
+N
+15.6913 555.844 m
+15.6913 555.844 l
+15.6913 548.614 21.5553 542.75 28.7853 542.75 c
+36.0163 542.75 41.8833 548.614 41.8833 555.844 c
+41.8833 563.075 36.0163 568.938 28.7853 568.938 c
+21.5553 568.938 15.6913 563.075 15.6913 555.844 c
+15.6913 555.844 l
+C
+S 0 0 0 r f R
+
+N
+16.8833 555.844 m
+16.8833 555.844 l
+16.8833 549.27 22.2113 543.942 28.7853 543.942 c
+35.3593 543.942 40.6913 549.27 40.6913 555.844 c
+40.6913 562.418 35.3593 567.747 28.7853 567.747 c
+22.2113 567.747 16.8833 562.418 16.8833 555.844 c
+16.8833 555.844 l
+C
+S 1 0.5 1 r f R
+
+N
+107.355 555.844 m
+107.355 555.844 l
+107.355 548.614 113.223 542.75 120.453 542.75 c
+127.683 542.75 133.547 548.614 133.547 555.844 c
+133.547 563.075 127.683 568.938 120.453 568.938 c
+113.223 568.938 107.355 563.075 107.355 555.844 c
+107.355 555.844 l
+C
+S 0 0 0 r f R
+
+N
+108.547 555.844 m
+108.547 555.844 l
+108.547 549.27 113.879 543.942 120.453 543.942 c
+127.027 543.942 132.355 549.27 132.355 555.844 c
+132.355 562.418 127.027 567.747 120.453 567.747 c
+113.879 567.747 108.547 562.418 108.547 555.844 c
+108.547 555.844 l
+C
+S 1 0 1 r f R
+
+N
+199.019 555.844 m
+199.019 555.844 l
+199.019 548.614 204.887 542.75 212.117 542.75 c
+219.348 542.75 225.211 548.614 225.211 555.844 c
+225.211 563.075 219.348 568.938 212.117 568.938 c
+204.887 568.938 199.019 563.075 199.019 555.844 c
+199.019 555.844 l
+C
+S 0 0 0 r f R
+
+N
+200.211 555.844 m
+200.211 555.844 l
+200.211 549.27 205.543 543.942 212.117 543.942 c
+218.691 543.942 224.019 549.27 224.019 555.844 c
+224.019 562.418 218.691 567.747 212.117 567.747 c
+205.543 567.747 200.211 562.418 200.211 555.844 c
+200.211 555.844 l
+C
+S 1 0.5 1 r f R
+
+N
+277.59 555.844 m
+277.59 555.844 l
+277.59 548.614 283.457 542.75 290.687 542.75 c
+297.918 542.75 303.781 548.614 303.781 555.844 c
+303.781 563.075 297.918 568.938 290.687 568.938 c
+283.457 568.938 277.59 563.075 277.59 555.844 c
+277.59 555.844 l
+C
+S 0 0 0 r f R
+
+N
+278.781 555.844 m
+278.781 555.844 l
+278.781 549.27 284.113 543.942 290.687 543.942 c
+297.262 543.942 302.59 549.27 302.59 555.844 c
+302.59 562.418 297.262 567.747 290.687 567.747 c
+284.113 567.747 278.781 562.418 278.781 555.844 c
+278.781 555.844 l
+C
+S 1 0 1 r f R
+
+N
+369.258 555.844 m
+369.258 555.844 l
+369.258 548.614 375.121 542.75 382.351 542.75 c
+389.582 542.75 395.445 548.614 395.445 555.844 c
+395.445 563.075 389.582 568.938 382.351 568.938 c
+375.121 568.938 369.258 563.075 369.258 555.844 c
+369.258 555.844 l
+C
+S 0 0 0 r f R
+
+N
+370.445 555.844 m
+370.445 555.844 l
+370.445 549.27 375.777 543.942 382.351 543.942 c
+388.926 543.942 394.258 549.27 394.258 555.844 c
+394.258 562.418 388.926 567.747 382.351 567.747 c
+375.777 567.747 370.445 562.418 370.445 555.844 c
+370.445 555.844 l
+C
+S 1 0 1 r f R
+
+N
+460.922 555.844 m
+460.922 555.844 l
+460.922 548.614 466.785 542.75 474.016 542.75 c
+481.246 542.75 487.109 548.614 487.109 555.844 c
+487.109 563.075 481.246 568.938 474.016 568.938 c
+466.785 568.938 460.922 563.075 460.922 555.844 c
+460.922 555.844 l
+C
+S 0 0 0 r f R
+
+N
+462.113 555.844 m
+462.113 555.844 l
+462.113 549.27 467.441 543.942 474.016 543.942 c
+480.59 543.942 485.922 549.27 485.922 555.844 c
+485.922 562.418 480.59 567.747 474.016 567.747 c
+467.441 567.747 462.113 562.418 462.113 555.844 c
+462.113 555.844 l
+C
+S 1 0.5 1 r f R
+
+N
+539.492 555.844 m
+539.492 555.844 l
+539.492 548.614 545.355 542.75 552.586 542.75 c
+559.816 542.75 565.68 548.614 565.68 555.844 c
+565.68 563.075 559.816 568.938 552.586 568.938 c
+545.355 568.938 539.492 563.075 539.492 555.844 c
+539.492 555.844 l
+C
+S 0 0 0 r f R
+
+N
+540.683 555.844 m
+540.683 555.844 l
+540.683 549.27 546.012 543.942 552.586 543.942 c
+559.16 543.942 564.492 549.27 564.492 555.844 c
+564.492 562.418 559.16 567.747 552.586 567.747 c
+546.012 567.747 540.683 562.418 540.683 555.844 c
+540.683 555.844 l
+C
+S 1 0 1 r f R
+
+N
+631.156 555.844 m
+631.156 555.844 l
+631.156 548.614 637.019 542.75 644.25 542.75 c
+651.48 542.75 657.348 548.614 657.348 555.844 c
+657.348 563.075 651.48 568.938 644.25 568.938 c
+637.019 568.938 631.156 563.075 631.156 555.844 c
+631.156 555.844 l
+C
+S 0 0 0 r f R
+
+N
+632.348 555.844 m
+632.348 555.844 l
+632.348 549.27 637.676 543.942 644.25 543.942 c
+650.824 543.942 656.156 549.27 656.156 555.844 c
+656.156 562.418 650.824 567.747 644.25 567.747 c
+637.676 567.747 632.348 562.418 632.348 555.844 c
+632.348 555.844 l
+C
+S 1 0.5 1 r f R
+
+N
+722.82 555.844 m
+722.82 555.844 l
+722.82 548.614 728.687 542.75 735.918 542.75 c
+743.149 542.75 749.012 548.614 749.012 555.844 c
+749.012 563.075 743.149 568.938 735.918 568.938 c
+728.687 568.938 722.82 563.075 722.82 555.844 c
+722.82 555.844 l
+C
+S 0 0 0 r f R
+
+N
+724.012 555.844 m
+724.012 555.844 l
+724.012 549.27 729.344 543.942 735.918 543.942 c
+742.492 543.942 747.82 549.27 747.82 555.844 c
+747.82 562.418 742.492 567.747 735.918 567.747 c
+729.344 567.747 724.012 562.418 724.012 555.844 c
+724.012 555.844 l
+C
+S 1 0 1 r f R
+
+N
+801.391 555.844 m
+801.391 555.844 l
+801.391 548.614 807.254 542.75 814.484 542.75 c
+821.715 542.75 827.578 548.614 827.578 555.844 c
+827.578 563.075 821.715 568.938 814.484 568.938 c
+807.254 568.938 801.391 563.075 801.391 555.844 c
+801.391 555.844 l
+C
+S 0 0 0 r f R
+
+N
+802.582 555.844 m
+802.582 555.844 l
+802.582 549.27 807.91 543.942 814.484 543.942 c
+821.059 543.942 826.387 549.27 826.387 555.844 c
+826.387 562.418 821.059 567.747 814.484 567.747 c
+807.91 567.747 802.582 562.418 802.582 555.844 c
+802.582 555.844 l
+C
+S 1 0 1 r f R
+
+N
+15.6913 32.047 m
+15.6913 32.047 l
+15.6913 24.8165 21.5553 18.9493 28.7853 18.9493 c
+36.0163 18.9493 41.8833 24.8165 41.8833 32.047 c
+41.8833 39.2775 36.0163 45.1407 28.7853 45.1407 c
+21.5553 45.1407 15.6913 39.2775 15.6913 32.047 c
+15.6913 32.047 l
+C
+S 0 0 0 r f R
+
+N
+16.8833 32.047 m
+16.8833 32.047 l
+16.8833 25.4728 22.2113 20.1407 28.7853 20.1407 c
+35.3593 20.1407 40.6913 25.4728 40.6913 32.047 c
+40.6913 38.6212 35.3593 43.9493 28.7853 43.9493 c
+22.2113 43.9493 16.8833 38.6212 16.8833 32.047 c
+16.8833 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+94.2623 32.047 m
+94.2623 32.047 l
+94.2623 24.8165 100.125 18.9493 107.355 18.9493 c
+114.586 18.9493 120.453 24.8165 120.453 32.047 c
+120.453 39.2775 114.586 45.1407 107.355 45.1407 c
+100.125 45.1407 94.2623 39.2775 94.2623 32.047 c
+94.2623 32.047 l
+C
+S 0 0 0 r f R
+
+N
+95.4533 32.047 m
+95.4533 32.047 l
+95.4533 25.4728 100.781 20.1407 107.355 20.1407 c
+113.93 20.1407 119.262 25.4728 119.262 32.047 c
+119.262 38.6212 113.93 43.9493 107.355 43.9493 c
+100.781 43.9493 95.4533 38.6212 95.4533 32.047 c
+95.4533 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+159.734 32.047 m
+159.734 32.047 l
+159.734 24.8165 165.601 18.9493 172.832 18.9493 c
+180.062 18.9493 185.926 24.8165 185.926 32.047 c
+185.926 39.2775 180.062 45.1407 172.832 45.1407 c
+165.601 45.1407 159.734 39.2775 159.734 32.047 c
+159.734 32.047 l
+C
+S 0 0 0 r f R
+
+N
+160.926 32.047 m
+160.926 32.047 l
+160.926 25.4728 166.258 20.1407 172.832 20.1407 c
+179.406 20.1407 184.734 25.4728 184.734 32.047 c
+184.734 38.6212 179.406 43.9493 172.832 43.9493 c
+166.258 43.9493 160.926 38.6212 160.926 32.047 c
+160.926 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+238.305 32.047 m
+238.305 32.047 l
+238.305 24.8165 244.172 18.9493 251.402 18.9493 c
+258.633 18.9493 264.496 24.8165 264.496 32.047 c
+264.496 39.2775 258.633 45.1407 251.402 45.1407 c
+244.172 45.1407 238.305 39.2775 238.305 32.047 c
+238.305 32.047 l
+C
+S 0 0 0 r f R
+
+N
+239.496 32.047 m
+239.496 32.047 l
+239.496 25.4728 244.828 20.1407 251.402 20.1407 c
+257.976 20.1407 263.305 25.4728 263.305 32.047 c
+263.305 38.6212 257.976 43.9493 251.402 43.9493 c
+244.828 43.9493 239.496 38.6212 239.496 32.047 c
+239.496 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+303.781 32.047 m
+303.781 32.047 l
+303.781 24.8165 309.644 18.9493 316.875 18.9493 c
+324.105 18.9493 329.973 24.8165 329.973 32.047 c
+329.973 39.2775 324.105 45.1407 316.875 45.1407 c
+309.644 45.1407 303.781 39.2775 303.781 32.047 c
+303.781 32.047 l
+C
+S 0 0 0 r f R
+
+N
+304.973 32.047 m
+304.973 32.047 l
+304.973 25.4728 310.301 20.1407 316.875 20.1407 c
+323.449 20.1407 328.781 25.4728 328.781 32.047 c
+328.781 38.6212 323.449 43.9493 316.875 43.9493 c
+310.301 43.9493 304.973 38.6212 304.973 32.047 c
+304.973 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+382.351 32.047 m
+382.351 32.047 l
+382.351 24.8165 388.215 18.9493 395.445 18.9493 c
+402.676 18.9493 408.543 24.8165 408.543 32.047 c
+408.543 39.2775 402.676 45.1407 395.445 45.1407 c
+388.215 45.1407 382.351 39.2775 382.351 32.047 c
+382.351 32.047 l
+C
+S 0 0 0 r f R
+
+N
+383.543 32.047 m
+383.543 32.047 l
+383.543 25.4728 388.871 20.1407 395.445 20.1407 c
+402.019 20.1407 407.351 25.4728 407.351 32.047 c
+407.351 38.6212 402.019 43.9493 395.445 43.9493 c
+388.871 43.9493 383.543 38.6212 383.543 32.047 c
+383.543 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+447.828 32.047 m
+447.828 32.047 l
+447.828 24.8165 453.691 18.9493 460.922 18.9493 c
+468.152 18.9493 474.016 24.8165 474.016 32.047 c
+474.016 39.2775 468.152 45.1407 460.922 45.1407 c
+453.691 45.1407 447.828 39.2775 447.828 32.047 c
+447.828 32.047 l
+C
+S 0 0 0 r f R
+
+N
+449.016 32.047 m
+449.016 32.047 l
+449.016 25.4728 454.348 20.1407 460.922 20.1407 c
+467.496 20.1407 472.824 25.4728 472.824 32.047 c
+472.824 38.6212 467.496 43.9493 460.922 43.9493 c
+454.348 43.9493 449.016 38.6212 449.016 32.047 c
+449.016 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+526.394 32.047 m
+526.394 32.047 l
+526.394 24.8165 532.262 18.9493 539.492 18.9493 c
+546.723 18.9493 552.586 24.8165 552.586 32.047 c
+552.586 39.2775 546.723 45.1407 539.492 45.1407 c
+532.262 45.1407 526.394 39.2775 526.394 32.047 c
+526.394 32.047 l
+C
+S 0 0 0 r f R
+
+N
+527.586 32.047 m
+527.586 32.047 l
+527.586 25.4728 532.918 20.1407 539.492 20.1407 c
+546.066 20.1407 551.394 25.4728 551.394 32.047 c
+551.394 38.6212 546.066 43.9493 539.492 43.9493 c
+532.918 43.9493 527.586 38.6212 527.586 32.047 c
+527.586 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+591.871 32.047 m
+591.871 32.047 l
+591.871 24.8165 597.734 18.9493 604.965 18.9493 c
+612.195 18.9493 618.062 24.8165 618.062 32.047 c
+618.062 39.2775 612.195 45.1407 604.965 45.1407 c
+597.734 45.1407 591.871 39.2775 591.871 32.047 c
+591.871 32.047 l
+C
+S 0 0 0 r f R
+
+N
+593.062 32.047 m
+593.062 32.047 l
+593.062 25.4728 598.39 20.1407 604.965 20.1407 c
+611.539 20.1407 616.871 25.4728 616.871 32.047 c
+616.871 38.6212 611.539 43.9493 604.965 43.9493 c
+598.39 43.9493 593.062 38.6212 593.062 32.047 c
+593.062 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+N
+670.441 32.047 m
+670.441 32.047 l
+670.441 24.8165 676.305 18.9493 683.535 18.9493 c
+690.766 18.9493 696.633 24.8165 696.633 32.047 c
+696.633 39.2775 690.766 45.1407 683.535 45.1407 c
+676.305 45.1407 670.441 39.2775 670.441 32.047 c
+670.441 32.047 l
+C
+S 0 0 0 r f R
+
+N
+671.633 32.047 m
+671.633 32.047 l
+671.633 25.4728 676.961 20.1407 683.535 20.1407 c
+690.109 20.1407 695.441 25.4728 695.441 32.047 c
+695.441 38.6212 690.109 43.9493 683.535 43.9493 c
+676.961 43.9493 671.633 38.6212 671.633 32.047 c
+671.633 32.047 l
+C
+S 0 0 1 r f R
+
+N
+735.918 32.047 m
+735.918 32.047 l
+735.918 24.8165 741.781 18.9493 749.012 18.9493 c
+756.242 18.9493 762.106 24.8165 762.106 32.047 c
+762.106 39.2775 756.242 45.1407 749.012 45.1407 c
+741.781 45.1407 735.918 39.2775 735.918 32.047 c
+735.918 32.047 l
+C
+S 0 0 0 r f R
+
+N
+737.105 32.047 m
+737.105 32.047 l
+737.105 25.4728 742.437 20.1407 749.012 20.1407 c
+755.586 20.1407 760.914 25.4728 760.914 32.047 c
+760.914 38.6212 755.586 43.9493 749.012 43.9493 c
+742.437 43.9493 737.105 38.6212 737.105 32.047 c
+737.105 32.047 l
+C
+S 0 0 1 r f R
+
+N
+801.391 32.047 m
+801.391 32.047 l
+801.391 24.8165 807.254 18.9493 814.484 18.9493 c
+821.715 18.9493 827.578 24.8165 827.578 32.047 c
+827.578 39.2775 821.715 45.1407 814.484 45.1407 c
+807.254 45.1407 801.391 39.2775 801.391 32.047 c
+801.391 32.047 l
+C
+S 0 0 0 r f R
+
+N
+802.582 32.047 m
+802.582 32.047 l
+802.582 25.4728 807.91 20.1407 814.484 20.1407 c
+821.059 20.1407 826.387 25.4728 826.387 32.047 c
+826.387 38.6212 821.059 43.9493 814.484 43.9493 c
+807.91 43.9493 802.582 38.6212 802.582 32.047 c
+802.582 32.047 l
+C
+S 0.5 0.5 1 r f R
+
+%%EOF