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<> and != (Not Equal)

Evaluates if two values aren’t equivalent.

Description: Evaluates if two values aren’t equivalent.
Use: expression1 <> expression2 or expression1 != expression2, and replace each expression with merge fields, expressions, or other numeric values.
Example: 
IF(Maint_Amount__c + Services_Amount__c<> Amount, 
 "DISCOUNTED", "FULL PRICE")

This formula displays DISCOUNTED on a product if its maintenance amount and services amount don’t equal the product amount. Otherwise, displays FULL PRICE. Note that this example uses two custom currency fields for Maint Amount and Services Amount.
Important
Important Don’t use this function for a null comparison, such as MyDateTime__c != null. Use ISBLANK instead.

Use

expression1 <> expression2 or expression1 != expression2, and replace each expression with merge fields, expressions, or other numeric values.

Discount Example
Discount Example 
IF(Maint_Amount__c + Services_Amount__c<> Amount, 
 "DISCOUNTED", "FULL PRICE")

This formula displays DISCOUNTED on a product if its maintenance amount and services amount don’t equal the product amount. Otherwise, displays FULL PRICE. Note that this example uses two custom currency fields for Maint Amount and Services Amount.