Definitions

 
Below I will use two terms that you will need to understand precisely:
 
"Cold-tire temperature" is your tire's temperature in the shade, before riding, in the coldest time of your riding day.  For most, this will be in the morning after resting overnight, before any sunlight hits your tires.
 
"Cold-tire pressure" is vehicle manufacturer's recommended pressure when the tires are at their "cold-tire temperature" (or the adjusted pressure you may have adopted after experimenting with tire wear and performance).  This pressure forms the "baseline pressure" for some computations below.
 
The symbol "*" is used below to indicate multiplication, so as to be more explicit.  Example:  "3 * T" (meaning 3 multiplied times T) is more explicit than just "3T".

Made with help of Dr.Explain