Hopefully you’re vaguely aware that means "a multiplied by itself b times" (for )11 1 If you’re not sure about this notation, review the section on ”Sets and Numbers”. From this definition, there are a bunch of useful facts we can derive.
A somewhat non-rigorous argument for this being true is as follows: (a times itself b times). When we multiply by , which is equal to (a times itself c times), we are then multiplying times itself times by times itself times. Overall, therefore we are multiplying by itself times.
To see that this is true, first note that we start by multiplying by itself times (). We then raise this to the power of , so , which means we have . In total, there are lots of (every bracket is lots of , and there are of the brackets, so overall there are lots of ).