We will make a construction of twisted equivariant
K-theory for proper actions of discrete groups by using ideas of Lück and Oliver (Topology 40:585–616, 2001) to expand a construction
of Adem and Ruan (Comm. Math. Phys. 237:533–556, 2003).
Keywords Twisted equivariant K-theory - Twisted Bredon cohomology - Proper actions - Discrete groups