AlterQuery  t_light (children 3)
 ExpressionList (children 1)
  AlterCommand UPDATE (children 2)
   Function less (children 1)
    ExpressionList (children 2)
     Identifier a
     Literal UInt64_3
   ExpressionList (children 1)
    Assignment b (children 1)
     Literal Int64_-1
 Identifier t_light
 Set
