module leakint {                                          # leaky integration
real ::    rho
#%  _init( rho)
#%  _lop ( xx,  yy)
integer i, n       
real tt
n = size (xx); tt = 0.
if( adj)
	do i= n, 1, -1 {   tt = rho*tt + yy(i)
		xx(i)  +=  tt
		}
else
	do i= 1, n {       tt  = rho*tt + xx(i)
		yy(i)  +=  tt
        	}
}