**(1)** A programming conflict whereby the operation of each of two routines requires the result from the other routine. See

recursion.

**(2)** In a spreadsheet, a conflict in which the formula computes the cell that the formula itself is located in. For example, a formula in cell A9 that sums the values of "A7 + A8 + A9" is a circular reference.

**A Spreadsheet Warning**
Circular references are identified in spreadsheets. However, this Excel example does not indicate which cell is the problem.