| 15 | 
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 | continue | 
| 16 | 
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 | if then | |
| 17 | 
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 | continue | 
| 18 | 
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 | //generating the next layer of the searching tree | |
| 19 | 
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 | for all in such that do | |
| 20 | 
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| 21 | 
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| 22 | 
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| 23 | 
 | 
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| 24 | 
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 | if then | 
| 25 | 
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| 26 | 
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 | |
| 27 | 
 | return QAbNI | ||