PowerPivot case: Does a value exist in both columns ?

I had a interesting question on my ask a questions page that I wanted to answer by solving it using PowerPivot.The following question was asked:

If i have a powerpivot table whith phone numbers in two different columns. Can i make some kind if a search formula if i want to search a specifik number in each column or if the number exits in one or both columns?

Ok lets solve it. I have the following table in PowerPivot:

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