Guide: functions

Just a few words about functions and defining them.
No—there’s nothing wrong<sup>[[1]](http://blog.oxforddictionaries.com/2012/01/can-i-start-a-sentence-with-a-conjunction/)</sup> with starting a sentence with a conjunction. And this is a very common misconception<sup>[[2]](https://en.wikipedia.org/wiki/Common_English_usage_misconceptions#Grammar)</sup>—it’s often taught in schools even though there’s no reason at all for it. Some ~10% of English sentences begin with conjunctions, so trying to adhere to this rule can be awkward.