Errata for "SPARK: Top-k Keyword Query in Relational Databases" 

1) Algorithm 1, Line 12 (Page 7): "if t.i > 1 then" should be "if
   head.i > 1 then".

2) Table 2 (Page 3): there are another two valid CNs of size 3 (listed
   below):

   ----------------------------------------------------------------------
   Size    CN ID     CN                      Valid?      Violates
   ----------------------------------------------------------------------
   3       CN_5   C^Q -> P <- C^Q              Y         
   3       CN_6   C^Q -> U <- C^Q              Y         
   ----------------------------------------------------------------------