SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 1) Function substring (children 1) ExpressionList (children 2) Function toFixedString (children 1) ExpressionList (children 2) Literal \'abc\' Literal UInt64_3 Function minus (children 1) ExpressionList (children 2) Identifier number Literal UInt64_5 TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier system.numbers Literal UInt64_10