Function XYZ is an array function

Answer:

An array function is a function that returns multiple values (i.e. an array of values). For instance, the DIFF function returns the whole time series of the differenced time series.

An array function returns the value of the first element by default. To expand the values, please

1. Select all cells column-wise (starting from the cell with formula).
   
2. Press F2 or click in the formula bar to enter the formula edit mode.
   
3. Press CTRL+SHIFT+ENTER together.
   
4. If successful, you will see the formula enclosed between italic braces (i.e. {}).