Create customer column based on boolean values & dates of other columns

Hi, I'm trying to create a custom column for inventory purposes. There are two relevant columns I need to include in the formula:

• Product EUD (End Use Date) - indicates the date that a product's available resources (e.g. amount of liquid in a bottle) depleted
• Out of Possession - (boolean) indicates that the product is no longer available for use (e.g. if it is depleted)

The data I'm bringing into PQ is already populated with some of this data, but I want the custom column to populate via a check on the existing data. The logic would be something like this:

• If Out_of_Possession is not null
  • use existing value
• Else
  • if Product_EUD is null
    • FALSE
  • else
    • TRUE

How can I create a custom column formula to capture this logic? I'm having some difficulty composing it with the M language.