1. Agilent Laboratories, 3500 Deer Creek Road, Palo Alto, CA 94304, and Department of Computer Science and Engineering, University of Washington, Seattle, WA 98195.
2. International Computer Science Institute, University of California at Berkeley, Berkeley, CA 94704.
3. Department of Computer Science and Engineering, University of Washington, Seattle, WA 98195 and Institute for Systems Biology, Seattle, WA 98105.
4. Agilent Laboratories, 3500 Deer Creek Road, Palo Alto, CA 94304 and Computer Science Department, Technion, Haifa 32000, Israel.