yo identifico los bajos asi ej:
7.1
8.2
9.3
10.4
11.5
12.6
intro ...
4.c
6.c
4.a
10.c
12.c
10.c
4.a
4.a
6.c
8.c
6.c
////
////
////
4.c
12.c
10.c
4.c
7.1
8.2
9.3
10.4
11.5
12.6
intro ...
4.c
6.c
4.a
10.c
12.c
10.c
4.a
4.a
6.c
8.c
6.c
////
////
////
4.c
12.c
10.c
4.c