DYING, LYING, TYING

http://snowball.tartarus.org/algorithms/english/stemmer.html says:

    b) Similarly there is a problem with the ing form of three letter verbs
    ending ie. There are only three such verbs: die, lie and tie, so a special
    case is made for dying, lying and tying. 

However, there's also "vie" -> "vying" and, more obscurely, "hie" -> "hying".

Perhaps this rule should be slightly generalised to:

<non-vowel>ying -> <non-vowel>ie ?

This change doesn't seem to adversely affect any real words, and may help
slang/neologisms which follow the X-ie -> X-ying pattern:

http://www.urbandictionary.com/define.php?term=Pying
http://www.urbandictionary.com/define.php?term=Rying

Cheers,
    Olly