#define FT(i,j,k) ((*this)(subseed,i+x,j+y,k+t)*(R((i)-a)*R(b-(j))*R((k)-c)))
#define Z(i,j) ret+=F(i,j)
#define ZT(i,j,k) ret+=FT(i,j,k)
-#define X(i,j) // placeholder... To make box more symetric
-#define XT(i,j,k) // placeholder... To make box more symetric
+#define X(i,j) // placeholder... To make box more symmetric
+#define XT(i,j,k) // placeholder... To make box more symmetric
float a(xf-x), b(yf-y);