What is the format/syntax to use Operators in OIC assign actions?

Summary:

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I need to assign variable values conditionally. I know XSLT is available in mapping but not in the assign action. There are conditional functions listed in Operators, but I don't know the syntax. There is only one box so where do I put the condition and where do I put the corresponding value?

Version (include the version you are using, if applicable): OIC 3

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