function TilesInCity(city)
{
    tiles = AITileList();
    neighbors = AITileList();

    function AddNeighbor(tile)
    {
        if ( AITown.IsWithinTownInfuence(city, tile) )
        {
            neighbors.AddTile(tile);
            tiles.AddTile(tile);
        }
    }

    while ( neighbors.Count() > 0 )
    {
        t = neighbors.Begin();
        neighbors.RemoveTop(1);

        // orthogonals
        AddNeighbor(tile - AIMap.GetTileIndex(1,0));
        AddNeighbor(tile - AIMap.GetTileIndex(0,1));
        AddNeighbor(tile - AIMap.GetTileIndex(-1,0));
        AddNeighbor(tile - AIMap.GetTileIndex(0,-1));
    }

    return tiles;
}

function CityOutletRoads(city)
{
    outlets = AITileList();

    function IsOutlet(tile)
    {
        if ( !AIRoad.IsRoadTile(tile) )
            return false;

        neighbors = [
            tile - AIMap.GetTileIndex(1,0),
            tile - AIMap.GetTileIndex(1,1),
            tile - AIMap.GetTileIndex(0,1)
            tile - AIMap.GetTileIndex(0,0)
        ];

        neighboringRoads = 0;

        foreach ( tile in neighbors )
        {
            if ( !AITile.IsBuildable(tile) )
                return false;

            if ( AIRoad.IsRoadTile(tile) )
                neighboringRoads++;
        }

        return neighboringRoads == 1;
    }

    foreach ( tile, val in TilesInCity(city) )
    {
        if ( IsOutlet(tile) )
            outlets.AddTile(tile);
    }

    return outlets;
}