Bence, Merriman and Osher [BMO] have proposed a new numerical algorith
m for computing mean curvature flow, in terms of solutions of the usua
l heat equation, continually reinitialized after short time steps. Thi
s paper employs nonlinear semigroup theory to reconcile their algorith
m with the ''level-set'' approach to mean curvature flow of Osher-Seth
ian [OS], Evans-Spruck [ES], and Chen-Giga-Goto [CGG].