A reason was given: people found your post unclear.
To fix? Learn to write more clearly. For example, compare your formulation of "pseudorelational semigroup" with, say, how textbooks formulate the notion of "group" or "vector space".
Assuming you have coherent ideas, you are probably suffering from the problem that you have lots of details in your head that you aren't writing down, and are having trouble recognizing that the details are missing because you know the details and mentally fill them in when you read your writings.
Additionally, "link-only posts" — posts that have some (or especially all) of their essential content on another website — are strongly discouraged.