What began as a competition to appease a member of royalty's birthday wishes, continued on to not only introduce an entirely new area of mathematical studies but also to leave one particular question to remain without a complete and substantiated...
steps required to represent the knot as a polygon in the cubic lattice. Several lower bounds for the lattice step numbers of different knots have been obtained by computer simulations but the exact value of the lattice step number seems to be ...
In this paper Euclidean and hyperbolic discontinuous isometries* are discussed and compared. The graphic artist M.C. Escher (1898-1972) produced works which have for the structure points, lines, and angles, which repeat in the plane (Euclidean and...
