Pictures on the cover were created by Jordi Vives Nebot
(Dept. de Fisica Fonamental, Universitat de Barcelona, Diagonal 647, E08028,
Barcelona, Spain). They represent sections x + ye_{12} +
ze_{1} of two Juliatype 3dimensional Clifford fractals
viewed from an isometric perspective. Each image is a result of 10
iterations of the map c > c^{2} + b, where c and b are elements
of the Clifford algebra Cl_{p,q}, p+q=2. Convergence
of the resulting sequences of Clifford elements was determined by using
a spinorial norm (the scalar part of the Clifford number times it Cliffordconjugate).
The following metrics and base points b have been used to create these
images:

Plane Fractal: b= 0.152815 + 0.656528e_{12} in Cl_{2,0};

Quaternionic Fractal: b= 0.152815 + 0.5e_{1} + 0.656528e_{12}
in Cl_{0,2}.
Last revised: Feb 14, 2002