Fixed typo in explanation page

Author: evildmp

explanation.rst

@@ -16,7 +16,7 @@ Explanation deepens and broadens the reader's understanding of a subject. It bri
 
 The concept of *reflection* is important. Reflection occurs *after* something else, and depends on something else, yet at the same time brings something new - shines a new light - on the subject matter.
 
-The perspective of explanation is higher and wider than that of the other not types. It does not take the user's eye-level view, as in a how-to guide, or a close-up view of the machinery, like reference material. Its scope in each case is a topic - "an area of knowledge", that somehow has to be bounded in a reasonable, meaningful way.
+The perspective of explanation is higher and wider than that of the other three types. It does not take the user's eye-level view, as in a how-to guide, or a close-up view of the machinery, like reference material. Its scope in each case is a topic - "an area of knowledge", that somehow has to be bounded in a reasonable, meaningful way.
 
 For the user, explanation joins things together. It's an answer to the question: *Can you tell me about ...?*
 
@@ -42,7 +42,7 @@ understanding of that craft, and needs the explanatory material that will help w
     * *Conceptual guides*
     * *Topics*
 
-The word *explanation* - and its cognates in other languages - refer to *unfolding*, the revelation of what is hidden in the folds. So explanation brings to the light things that were implicit or obscured. 
+The word *explanation* - and its cognates in other languages - refer to *unfolding*, the revelation of what is hidden in the folds. So explanation brings to the light things that were implicit or obscured.
 
 Similarly, words that mean *understanding* share roots in words meaning to hold or grasp (as in *comprehend*). That's an important part of understanding, to be able to hold something or be in possession of it. Understanding seals together the other components of our mastery of a craft, and makes it safely our own.
 
@@ -106,7 +106,7 @@ title. For example: *About user authentication*, or *About database connection p
 Admit opinion and perspective
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Opinion might seem like a funny thing to introduce into documentation. The fact is that all human activity and knowledge is invested within opinion, with beliefs and thoughts. The reality of any human creation is rich with opinion, and that needs to be part of any understanding of it. 
+Opinion might seem like a funny thing to introduce into documentation. The fact is that all human activity and knowledge is invested within opinion, with beliefs and thoughts. The reality of any human creation is rich with opinion, and that needs to be part of any understanding of it.
 
 Similarly, any understanding comes from a perspective, a particular stand-point - which means that other perspectives and stand-points exist. **Explanation can and must consider alternatives**, counter-examples or multiple different approaches to the same question.