Eliminate each knot crossing by connecting each of the strands coming into the crossing to the adjacent strand leaving the crossing. The resulting strands no longer cross but form instead a set of nonintersecting circles called Seifert circles.
Seifert Circle
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References
Adams, C. C. The Knot Book: An Elementary Introduction to the Mathematical Theory of Knots. New York: W. H. Freeman, p. 96, 1994.Referenced on Wolfram|Alpha
Seifert CircleCite this as:
Weisstein, Eric W. "Seifert Circle." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SeifertCircle.html