One uses as dynamical variables the complete strings {xp(t)} or probably better specifies them with a neural formalism inspired by Hopfield and Tank's traveling salesperson work |
Sp (x,t) = 0 if p is not at x time t |
Sp (x,t) = 1 if p is at x time t |
with constraint S Sp (x,t) = 1 (one string in field) |
The associated dynamics is that of interacting strings with usual repulsive and attractive forces plus creation and annihilation. |