Figure 9
A.) Coloring a knot. The three arcs are labeled x1, x2, x3. A coloring of this knot diagram must satisfy the three equations corresponding to the three crossings. B.) A 3-coloring of this knot. C.) Coloring a 2-string tangle. The eight arcs are labeled x1, x2, ..., x8. The six crossings result in six equations.