Proof

   TODO

   Why do we need mathematical proof if something is obvious? Well,
   mathematicians need to be most precise and proof enables them to discover
   absolute truths without any shadow of a doubt (a luxury most other
   scientists don't have), so they set it as a standard because many things
   that seem obvious aren't in fact so -- for example numbers 31, 331, 3331,
   33331, 333331, 3333331 and 33333331 are all [1]primes so you might think
   by this pattern also 333333331 will be a prime, but that's not the case
   because 333333331 = 19607843 * 17. Sometimes patterns deceive us,
   mathematicians only take proof for the ultimate solution. But indeed e.g.
   the industry sometimes accepts even unproven but highly likely conjectures
   to hold, e.g. that [2]P doesn't equal NP, simply for economic reasons (the
   chance of being wrong is very low and profitability of being right is
   high).

Links:
1. prime.md
2. p_vs_np.md