just comparing numbers?
Well, the pic is a risc µC, so there aren't any instructions that allow direct comparison of 2 variables, so you'll have to use tricks to get it done (as with any risc based system)
For example, if you want to see if number1 is bigger then number2 you just subtract number1 from number2 and if the borrow flag is set (a flag that indicates the result went below 0 and 'rolled over' back to 255) then number1 was bigger
To see if 2 numbers are the same you can XOR them, if they are the same then the result is 0