So this week we're going to develop a running model for the SLIP, the so-called spring-loaded inverted pendulum and what we're gonna do is we're going to go from bioinspiration, where we understand that this is the behavior that animals exhibit when they run over scales. We're going to take that inspiration, and we're going to develop from that idea of the spring-loaded inverted pendulum models of the stance mechanics that explain the way in which states at the bottom will be transformed into apex states at the top.