--- /dev/null
+method f1(a b)
+ return a - (-1 * b);
+end;
+
+method f2(a b)
+ return a - (-2 * b);
+end;
+
+method f4(a b)
+ return a - (-4 * b);
+end;
+
+method f8(a b)
+ return a - (-8 * b);
+end;
+
+method f(a b c d)
+ return a - (-8 * (b - (-4 * (c - (-2 * d)))));
+end;