DESIGN FOR A BRAIN 19/22 



then if the fr's are zero (as ean be arranged by a change of 

 origin) the equations may be written in matrix form as 



x = Ax . . . (6) 



where x and x are column vectors and A is the square matrix 

 [aij]. In matrix notation the solution may be written 



x = e tA x° .... (7) 



(3) Most convenient for actual solution of the linear form is 

 the recently developed method of the Laplace transform. The 

 standard text-books should be consulted for details. 



19/22. Any comparison of a state-determined system with the 

 other types of system treated in physics and thermodynamics 

 must be made with caution. Thus, it should be noticed that the 

 concept of the state-determined system makes no reference to 

 energy or its conservation, treating it as inelevant. It will also be 

 noticed that the state-determined system, whatever the ' machine ' 

 providing it, is essentially irreversible. This can be established 

 either by examining the behaviour representation of S. 19/7, the 

 canonical representation of S. 19/9, or, in a particular case, by 

 examining the field of the common pendulum in Figure 2/15/1. 



252 



