Integration Center - Calculated Field using If/Then/Else

Hi -

I am creating an integration between SuccessFactors and a vendor using Integration Center and require a calculated field/derived field. I am a bit confused on how the If/Then/Else clauses operate for a Calculated Field and need some assistance.

I am trying to evaluate a field and, if the field value is one of three values, display 'Yes', else, display 'No'

Example:

Evaluate Field 'Location'. If Location equals 'A', or 'B', or 'C', then display 'Yes', else, display 'No'. Seems straightforward, but I can't seem to get the If/Then If/Then/Else clauses to align where the proper results display.

If someone could help with the proper syntax or easier way to accomplish this, I would appreciate it!