Safe aspect composition

1 I3S { CNRS UPRESA 6070 { Bât ESSI, 06190 Sophia-Antipolis, France, bussard@essi.fr 2 IBM T. J. Watson Research Center, Yorktown Heights, NY, USA, lcarver@us.ibm.com 3 Dept. of Computer Science, University of Aalborg, Denmark, eernst@cs.auc.dk 4 Institut Eur ecom, 06190 Sophia Antipolis, France, jung@eurecom.fr 5 Dept. of Computer Science, University of British Columbia, Canada, mrobilla@cs.ubc.ca 6 Wilhelm-Schickard-Institute for Comp. Sci., U. of Tubingen, Germany, specku@informatik.uni-tuebingen.de