COMBINATORICA • Volume 20 • Number 4 • 2000
CONTENTS
NOGA ALON, ELDAR FISCHER, MICHAEL KRIVELEVICH, MARIO SZEGEDY:
Efficient testing of large graphs . . . 451 MALGORZATA BEDNARSKA, TOMASZ LUCZAK: Biased positional games for
which random strategies are nearly o p t i m a l . . . 477 ROBIN FORMAN: Morse theory and evasiveness . . . 489 JOEL FRIEDMAN: On Cayley graphs on the symmetric group generated by
t r a n p o s i t i o n s . . . 505 A. V. KOSTOCHKA, M. STIEBITZ: On the number of edges in colour-critical
graphs and hypergraphs . . . 521 BENOIT LAROSE, CLAUDE TARDIF: Hedetniemi's conjecture and the re-
tracts of a product of graphs . . . 531 NATHAN LINIAL, ALEX SAMORODNITSKY, AVI WIGDERSON: A determin-
istic strongly polynomial algorithm for matrix scaling and approx- imate p e r m a n e n t s . . . 545 LAJOS RONYAI: On a conjecture of Kemnitz . . . 569 ALEXANDER SCHRIJVER: Total dual integrality of matching forest con-
straints . . . 575 GEZA TOTH: Finding convex sets in convex p o s i t i o n . . . 589