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Can you see the isotopy between the Perko pair? My favourite pair. Find the writhe and linking number of this celtic earring. The reef knot decomposed into two trefoils - join ends and find the isotopy. Pictures of knots with 10 crossings taken from the tables of Tate and Little. The Perko pair is 5II and 6VI. Here 6VI is omitted.

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Here is an unknotting of a `Gordian knot'.

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Next lecture

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