CUHK MATH

Tie me up, Tie me down
 
Equivalence
Trefoil
Figure Eight
Whitehead
Trivial Knot
Perko Pairs
 
Classifications
Torus Knots
Alternating Knots
 
Invariants
Crossing number< br> Bridge number
Unknotting number< /a>
Tricolorability< br> Linking number Polynomials

compare the pictures and find the crossings needed to change