4 #define M1(A, B) ((A) < (B))  argument
5 #define M2(A, B) M1(A, B)  argument
6 #define M3(A, B) M2(A, B)  argument
7 #define M4(A, B) M3(A, B)  argument
8 #define M5(A, B) M4(A, B)  argument
9 #define M6(A, B) M5(A, B)  argument
10 #define M7(A, B) M6(A, B)  argument
11 #define M8(A, B) M7(A, B)  argument
12 #define M9(A, B) M8(A, B)  argument
13 #define M10(A, B) M9(A, B)  argument
14 #define M11(A, B) M10(A, B)  argument
15 #define M12(A, B) M11(A, B)  argument