fixedCombinations2 = 
  let Just url = importURL "http://c.c/page?a=1&a=2&a=3" in
 [ [("a","1"), ("a", "2")]
 , [("a","1"), ("a", "3")]
 , [("a", "2"), ("a", "1")]
 , [("a", "2"), ("a", "3")]
 , [("a", "3"), ("a", "1")]
 , [("a", "3"), ("a", "2")]
 ] @=? (map url_params $ fixedCombinations "a" 2 url)
fixedCombinations2 = 
  let Just url = importURL "http://c.c/page?a=1&a=2&a=3" in
 [ [("a","1"), ("a", "2")]
 , [("a","1"), ("a", "3")]
 , [("a", "2"), ("a", "1")]
 , [("a", "2"), ("a", "3")]
 , [("a", "3"), ("a", "1")]
 , [("a", "3"), ("a", "2")]
 ] @=? (map url_params $ fixedCombinations "a" 2 url)
fixedCombinations2 = 
  let Just url = importURL "http://c.c/page?a=1&a=2&a=3" in
 [ [("a","1"), ("a", "2")]
 , [("a","1"), ("a", "3")]
 , [("a", "2"), ("a", "1")]
 , [("a", "2"), ("a", "3")]
 , [("a", "3"), ("a", "1")]
 , [("a", "3"), ("a", "2")]
 ] @=? (map url_params $ fixedCombinations "a" 2 url)