Update expression type

Author: Clare Zheng (Shanghai Wicresoft Co Ltd)

articles/data-factory/connector-servicenow.md

@@ -149,7 +149,7 @@ To copy data from ServiceNow, set the source type in the copy activity to **Serv
 | type | The type property of the copy activity source must be set to: **ServiceNowV2Source** | Yes |
 | expression| Use the expression to read data. You can configure the expression in **Query builder**. It has the same usage as the condition builder in ServiceNow. For instructions on how to use it, see this [article](https://docs.servicenow.com/bundle/vancouver-platform-user-interface/page/use/common-ui-elements/concept/c_ConditionBuilder.html). You can also [use expression parameters](#using-expression-parameters).| No |
 | *Under `expression`* |  |  |
-| type | The expression type. Values can be Constant (default), Unary, Binary, and Field.  | No  |
+| type | The expression type. Values can be Constant (default), Unary, Binary, Field and Nary.  | No  |
 | value | The constant value. |Yes when the expression type is Constant or Field |
 | operators | The operator value. For more information about operators, see *Operators available for choice fields containing strings* section in this [article](https://docs.servicenow.com/bundle/vancouver-platform-user-interface/page/use/common-ui-elements/reference/r_OpAvailableFiltersQueries.html).| Yes when the expression type is Unary or Binary |
 | operands | List of expressions on which operator is applied.| Yes when the expression type is Unary or Binary |