28th Annual Symposium on Foundations of Computer Science, Oct. 12-14, 1987 / 21st Annual Symposium on Foundations of Computer Science : Syracuse, Oct. 13-15, 1980 / 27th annual Symposium on Foundations of Computer Science / 30th Annual Symposium on Foundations of Computer Science : October 30-November 1, 1989 / 22nd annual symposium on Foundations of Computer Science / 24th Annual Symposium on Foundations of Computer Science / 26th Annual Symposium on Foundations of Computer Science / 28th Annual Symposium on Foundations of Computer Science : 18th Annual Symposium on Foundations of Computer Science. 20th Annual Symposium on Foundations of Computer Science.