A FORMAL PROOF OF THE KEPLER CONJECTURE oleh THOMAS HALES, MARK ADAMS, GERTRUD BAUER, TAT DAT DANG, JOHN HARRISON, LE TRUONG HOANG, CEZARY KALISZYK, VICTOR MAGRON, SEAN MCLAUGHLIN, TAT THANG NGUYEN, QUANG TRUONG NGUYEN, TOBIAS NIPKOW, STEVEN OBUA, JOSEPH PLESO, JASON RUTE, ALEXEY SOLOVYEV, THI HOAI AN TA, NAM TRUNG TRAN, THI DIEP TRIEU, JOSEF URBAN, KY VU, ROLAND ZUMKELLER