I really like the illustrations and explanations. When can we expect the natural transformations chapter?
And also I think there is a small typo at the end of second to last paragraph.
"At the same time we have the category of groups, for example, which contains the category of monoids as a subcategory, as all monoids are groups etc.". The roles of monoids and groups are actually reversed - all groups are monoids, but not all monoids are groups.
And also I think there is a small typo at the end of second to last paragraph. "At the same time we have the category of groups, for example, which contains the category of monoids as a subcategory, as all monoids are groups etc.". The roles of monoids and groups are actually reversed - all groups are monoids, but not all monoids are groups.