Idempotence is a desirable property of systems whereby repeating an action has no effect. Mathematically, an operator is idempotent if f(f(x)) = f(x). Idempote

Idempotence is a desirable property of systems whereby repeating an action has no effect. Mathematically, an operator is idempotent if f(f(x)) = f(x). Idempotence is handy because it implies that one can retry safely if one isn't sure whether something succeeded or failed. Not sure if your file was saved? Save again! If it was indeed saved, the file continues to be saved. If the file was not saved, it is now. Yay. I would kill for such descriptions of every system I work with.