I'm knitting a hat and have hit a roadblock. The pattern for the hat's earflaps calls for a mitered double decrease in the center of the row (which is 17 stitches). I have no clue how to do this type of decrease (or maybe it is just a different name for a specific kind of double decrease?) I have combed through my knitting books and googled "mitered double decrease", but I have had no luck. Help? Please?