query: #title: Check westernmost point and easternmost point of countries
  # Complex constraint from [[Property talk:P1334]]
  #
  SELECT ?item ?westernmostPoint ?easternmostPoint ?dist
  {
      ?item wdt:P31/wdt:P279* wd:Q6256.
      ?item wdt:P1335 ?westernmostPoint .
      ?item wdt:P1334 ?easternmostPoint .
      BIND(geof:distance(?westernmostPoint, ?easternmostPoint) as ?dist) 
      FILTER (?dist < 1)
  }
  ORDER BY (?dist)