an:00955087
Zbl 0865.05066
Gutner, Shai
The complexity of planar graph choosability
EN
Discrete Math. 159, No. 1-3, 119-130 (1996).
00037310
1996
j
05C85 05C15 68R10
choosability; planar graph; decision problems; NP-hard
Margit Voigt gave examples of a planar graph which is not 4-choosable and a planar triangle-free graph which is not 3-choosable. The present author presents simpler examples. He also proves that the corresponding decision problems for planar graphs are NP-hard.
C.Thomassen (Lyngby)