Indicator function

An indicator function is like having a special button that turns on and off depending on whether something is true or false. Think of it like a light switch that you can flip up or down. If something is true, the button turns on and stays on, glowing brightly. If something is false, the button turns off and stays off, looking like any other button.

For example, let's pretend we have a button for whether it's raining outside. If it's raining, the button turns on and glows brightly. If it's not raining, the button turns off and looks like any other button.

Indicator functions are really helpful when you want to do some calculations or make some decisions based on certain conditions. They act like a signal to tell you whether you should move in one direction or another.

So, the bottom line is: An indicator function is a special button that turns on and off depending on whether something is true or false.