Start with the idea x=a+c. x can now be short hand for a+c. That may help? If you think of a theorem in the light that it is a giant function you can break i

Start with the idea x=a+c. x can now be short hand for a+c. That may help? If you think of a theorem in the light that it is a giant function you can break it down that way too. Like sprintf is shorthand for the monster of bit of code that is sprintf.