module icaf1 {                  # Internal Convolution, Adjoint is Filter. 1-D
integer :: lag
real, dimension (:), pointer :: xx
#%  _init ( xx, lag)
#%  _lop  ( bb,  yy)
integer   x,  b,   y
do b= 1, size(bb) {
        do y= 1+size(bb)-lag, size(yy)-lag+1 {    x= y - b + lag      

                if( adj)        bb(b) +=  yy(y) * xx(x)
		else            yy(y) +=  bb(b) * xx(x)
                }
        }
}