Neighbors - relational constraint

The network usc3110.net describing the counties neighboring relation is not connected. It has some components that consist of counties on islands.

To make the network connected we add an additional relation sea describing neighboring counties with “sea borders”.

  usc.paj       usc.nam       usc3110.paj
1 "25007"  1186 "Dukes"       1186
2 "25019"  1192 "Nantucket"   1192
3 "36047"  1818 "Kings"       1818
4 "36059"  1824 "Nassau"      1824
5 "36081"  1835 "Queens"      1835
6 "36085"  1837 "Richmond"    1837
7 "36103"  1846 "Suffolk"     1846
8 "53055"  2950 "San Juan"    2949

  "53057"  2951 "Skagit"      2950
  "53009"  2927 "Clallam"     2926
  "53029"  2937 "Island"      2936
  "53073"  2959 "Whatcom"     2958

  "25001"  1183 "Barnstable"  1183

  "36005"  1797 "Bronx"       1797
  "36061"  1825 "New York"    1825
  "36119"  1854 "Westchester" 1854
  "09001"   279 "Fairfield"    279
  "09007"   282 "Middlesex"    282
  "09009"   283 "New Haven"    283
  "09011"   284 "New London"   284
  "44009"  2282 "Washington"  2282
  "34023"  1752 "Middlesex"   1752
  "34025"  1753 "Monmouth"    1753
  "34039"  1760 "Union"       1760
  "34017"  1749 "Hudson"      1749

*Edges :3 "sea"
2949 2926 1
2949 2936 1
2949 2950 1
2949 2958 1
1183 1186 1
1183 1192 1
1186 1192 1
1846 2282 1
1846  284 1
1846  282 1
1846  283 1
1846  279 1
1824  279 1
1824 1854 1
1824 1797 1
1835 1797 1
1835 1825 1
1835 1749 1
1818 1825 1
1818 1749 1
1818 1837 1
1818 1753 1
1837 1760 1
1837 1752 1
1837 1753 1

The new relation is saved as usc3110+.paj.