SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 5) Identifier a1 Identifier b1 Identifier a2 Identifier b2 Function plus (children 1) ExpressionList (children 2) Identifier a2 Literal UInt64_1 TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier tab1 TablesInSelectQueryElement (children 2) TableExpression (children 1) TableIdentifier tab2 TableJoin (children 1) Function equals (children 1) ExpressionList (children 2) Function plus (children 1) ExpressionList (children 2) Identifier b1 Literal UInt64_1 Function plus (children 1) ExpressionList (children 2) Identifier a2 Literal UInt64_1