To humanity, the course of Nan Clan civilization's development was truly a history difficult to comprehend.
After "recording events with knotted cords," their civilization had taken a path utterly different from that of humanity.
As an arboreal species, the Nan Clan's ancestors possessed powerful three-dimensional spatial thinking, and their capacity for "abstraction" was no different from that of intelligent beings such as humans and dragons.
Thus, they had invented many knot-tying techniques very early on. Their tree-dwelling environment had also led to the widespread use of knots in many areas: securing branches to create living spaces; fastening themselves in midair to ward off predators; binding stones to trees to make primitive weapons, and so on.
Throughout this process, they gradually made their knots more complex. Ordinary knots alone had developed nearly a hundred tying methods.
Among the knot tables calculated by humanity [that is, tables listing the topological structures of knots], all relatively simple knots appeared in their "writing."
In other words, they knew how to tie every possible knot with no more than twelve crossings. To the Nan Clan, this was merely a basic survival skill.
And every knot had several variants.
As "writing," this was actually enough. Take Chinese characters on Earth: the total number had already exceeded ninety thousand, but only a little over three thousand five hundred were truly common. Mastering two to three thousand characters was enough for ordinary reading and writing. Even ancient masterpieces such as the Thirteen Classics involved only six thousand five hundred and forty-four characters.
Nearly a hundred kinds of knots, together with several equivalent variants, were enough to support a writing system that was not so primitive.
But that was not all. When many knots were combined, they could generate even more meanings.
In mathematics, this was called a "link"—a