Derivation steps in reasoning/mathematics. If you are learning mathematics, you might wonder if you should commit individual derivation steps of a mathematic proof or solution, or should you just focus on the final outcome. The choice will depend on your goals. If you only need the final formula, time spent on learning the derivation steps could be better spent learning other important portions of the material. If you are not sure today what you will need in the future, you could just type in the whole derivation into a single topic and memorize the final formula. Later, in incremental reading, you will make incremental decisions whether portions of the derivation are or are not important in your work or further learning. This piece of knowledge will compete with others in the learning process and in the long term you may ultimately decide if you want to memorize the details, keep them for passive review only, dismiss/delete some of the steps, or dismiss the entire derivation as redundant (or too costly to learn). Naturally, derivation will often enhance your ability to efficiently use the formula. Hence the decision is never easy. Once you have derivation steps committed, you can always play with their priority to determine the probability you will review them well enough to make a difference to your knowledge.