      psi(t,1) =   b(1,1) * exp( xlog(t-1,1)* b(2,1) 

     $           +  thedlog(t) * b(3,1) 

     $           +  xlog(t-1,2)* b(4,1))       

c     $           +  (xlog(t-1,1)*xlog(t-1,1)) * b(5,1)) 

      psi(t,2) =   b(1,2) * exp( xlog(t-1,1)* b(2,2) 

     $           + thedlog(t) * b(3,2) 

     $           + xlog(t-1,2) * b(4,2))      

c     $           + (xlog(t-1,1)*xlog(t-1,1)) * b(5,2)) 

       