2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/113377180) has short arc (4.32m) at http://www.openstreetmap.org/?mlat=51.10863&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/124267845) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.28785&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/124267799) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.28785&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173243603) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19256&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173242910) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19097&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173240413) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19058&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173240527) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19058&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173240483) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19037&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173238098) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19637&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174358111) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.23313&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/4611686018440972788) has short arc (1.50m) at http://www.openstreetmap.org/?mlat=51.06445&mlon=6.16593&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173235746) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19498&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173235188) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.20062&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173233604) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19498&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/4611686018440970866) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.14513&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173234070) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.20352&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173232418) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19281&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173232237) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19290&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173233045) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.19092&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/34377194) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.19595&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174369285) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.25804&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174367464) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.23139&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174254017) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.27796&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/129911824) has short arc (5.64m) at http://www.openstreetmap.org/?mlat=51.07990&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174255499) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.36246&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174255389) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.28386&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174255451) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.32928&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174255062) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.27798&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174358990) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.23358&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174254257) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.35739&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174254080) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.36917&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174257852) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.37145&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174257230) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.36999&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174257235) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.35789&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174256949) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.28062&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/174258215) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.32879&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/103060091) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.26581&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way Sint Lambertusweg (http://www.openstreetmap.org/browse/way/6706777) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.06591&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173855303) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.24620&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way Ernst-Reuter-Straße (http://www.openstreetmap.org/browse/way/24794923) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.27854&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way Mosterzstraße (http://www.openstreetmap.org/browse/way/24794924) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.27918&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173852742) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.28759&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/111851485) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.08235&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/50025050) has short arc (4.32m) at http://www.openstreetmap.org/?mlat=51.15631&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/50025045) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.16528&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/50025047) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.15241&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/50025046) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.16515&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/50025041) has short arc (4.32m) at http://www.openstreetmap.org/?mlat=51.16550&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173842218) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.29976&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/50670186) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.10844&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/19780836) has short arc (2.39m) at http://www.openstreetmap.org/?mlat=51.19597&mlon=6.37207&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/129448646) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.08934&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/129448641) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.08930&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/111856073) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.13707&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/111855929) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.13707&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/161288342) has short arc (4.50m) at http://www.openstreetmap.org/?mlat=51.06445&mlon=6.30308&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173848325) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.26364&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173845989) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.24712&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173845965) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.24620&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173846071) has short arc (5.63m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.29351&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/45847484) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.08735&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173844706) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.24562&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/129439387) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.08417&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/129439389) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.08479&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/129439405) has short arc (4.78m) at http://www.openstreetmap.org/?mlat=51.08475&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/173845131) has short arc (1.49m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.26143&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/49933267) has short arc (2.99m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.07849&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/49933263) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.08846&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/49933258) has short arc (5.98m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.09349&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/49933245) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.07235&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/125744538) has short arc (5.64m) at http://www.openstreetmap.org/?mlat=51.07231&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/199172714) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.23380&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/199171782) has short arc (4.48m) at http://www.openstreetmap.org/?mlat=51.28418&mlon=6.23373&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!
2013/01/27 03:25:12 WARNING (ElementSaver): 70013149.osm.pbf:   Way null (http://www.openstreetmap.org/browse/way/113252308) has short arc (4.32m) at http://www.openstreetmap.org/?mlat=51.18228&mlon=6.06445&zoom=17 - but it can't be removed because both ends of the arc are boundary nodes!