@InProceedings{sch-iclp-97,
  author = 	 {Peter Schachte},
  title = 	 {Global Variables in Logic Programming},
  booktitle = 	 {Logic Programming:  Proceedings of the Fourteenth
		  International Conference on Logic Programming.},
  year =	 {1997},
  editor =	 {Lee Naish},
  pages =	 {3--17},
  publisher =	 {MIT Press},
  address =	 {Cambridge, USA},
  month =	 {July},
  isbn =	 {0-262-64035-X},
  abstract =	 {We show that adding global variables to logic
		  programming can solve some common problems of
		  reliability and programmer productivity in large
		  logic programs.  By presenting a formal semantics
		  for logic programs with global variables, we show
		  that this addition retains a clean semantics.  This
		  addition has the consequences that conjunction is
		  neither commutative nor absorptive, but we show that
		  the practical loss is small.  We also describe an
		  implementation of Prolog with global variables as a
		  translator to ordinary Prolog which preserves the
		  efficiency of the Prolog program, while statically
		  detecting some programming errors, and avoiding
		  others altogether.}
}