+
−
def urbanmain() = {+
−
  import C2._+
−
+
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  val urban_list1 = List("a", "b", "b", "c", "d")+
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  val urban_list2 = List("d", "b", "d", "b", "d")+
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+
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  assert(prod(urban_list1, urban_list2) == 7)+
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  assert(prod(urban_list1, urban_list1) == 7)+
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  assert(prod(urban_list2, urban_list2) == 13)+
−
}+
−