DIOPHANTINE APPROXIMATION ON LINEAR ALGEBRAIC GROUPS: TRANSCENDENCE PROPERTIES OF THE EXPONENTIAL FUNCTION IN SEVERAL VARIABLES (Grundlehren der Mathematischen Wissenschaften 326) <i>By</i> M<scp>ICHEL</scp> W<scp>ALDSCHMIDT</scp>: 633 pp., $58.50, <scp>ISBN</scp> 3-540-66785-7 (Springer, Berlin, 2000).