diff --git a/ex-3/main.c b/ex-3/main.c
index 3b7948f..df87931 100644
--- a/ex-3/main.c
+++ b/ex-3/main.c
@@ -37,9 +37,9 @@ int main(int argc, char **argv) {
       fprintf(stderr, "\t-h\tShow this message.\n");
       fprintf(stderr, "\t-i\tPrint the histogram to stdout.\n");
       fprintf(stderr, "\t-I\tPrint *only* the histogram.\n");
-      fprintf(stderr, "\t-n N\tThe number of events to generate.\n");
-      fprintf(stderr, "\t-t N\tThe number of θ bins.\n");
-      fprintf(stderr, "\t-p N\tThe number of φ bins.\n");
+      fprintf(stderr, "\t-n N\tThe number of events to generate. (default: 50000)\n");
+      fprintf(stderr, "\t-t N\tThe number of θ bins. (default: 30)\n");
+      fprintf(stderr, "\t-p N\tThe number of φ bins. (default: 60)\n");
       return EXIT_FAILURE;
     }
   }
diff --git a/ex-4/main.c b/ex-4/main.c
index 03ecd2b..e2b0e4c 100644
--- a/ex-4/main.c
+++ b/ex-4/main.c
@@ -13,20 +13,20 @@ int parser(size_t *N, size_t *n, double *p_max, char argc, char **argv)
   {
   for (size_t i = 1; i < argc; i++)
     {
-         if (!strcmp(argv[i], "-N")) *N     = atol(argv[++i]);
-    else if (!strcmp(argv[i], "-n")) *n     = atol(argv[++i]);
+         if (!strcmp(argv[i], "-n")) *N     = atol(argv[++i]);
+    else if (!strcmp(argv[i], "-b")) *n     = atol(argv[++i]);
     else if (!strcmp(argv[i], "-p")) *p_max = atof(argv[++i]);
     else
       {
-      fprintf(stderr, "Usage: %s -[hiIntp]\n", argv[0]);
+      fprintf(stderr, "Usage: %s -[hnbp]\n", argv[0]);
       fprintf(stderr, "\t-h\tShow this message.\n");
-      fprintf(stderr, "\t-N integer\tThe number of events to generate.\n");
-      fprintf(stderr, "\t-n integer\tThe number of bins of the histogram.\n");
-      fprintf(stderr, "\t-p float\tThe maximum value of momentum.\n");
-      return EXIT_FAILURE;
+      fprintf(stderr, "\t-n N\tThe number of events to generate. (default: 50000)\n");
+      fprintf(stderr, "\t-b N\tThe number of bins of the histogram. (default: 50)\n");
+      fprintf(stderr, "\t-p PMAX\tThe maximum value of momentum. (default: 10)\n");
+      return 0;
       }
     }
-  return EXIT_SUCCESS;
+  return 1;
   }
 
 
@@ -39,10 +39,14 @@ int main(int argc, char **argv)
   size_t n = 50;             // number of bins.
   double p_max = 10;         // maximum value of momentum module.
   int res = parser(&N, &n, &p_max, argc, argv);
-  if (res == 0) printf("\nGenerating histogram with:\n"
+  if (res == 1)
+    {
+    printf("\nGenerating histogram with:\n"
                        "%ld points\n"
                        "%ld bins\n"
                        "p_max = %.3f\n\n", N, n, p_max);
+    }
+  else return EXIT_FAILURE;
 
   // printf("step: \t%.5f\n", step);
 
@@ -143,8 +147,8 @@ int main(int argc, char **argv)
   double x = 10;
   int    max_iter = 100;
   double prec = 1e-7;
-  int    status;
-  const gsl_min_fminimizer_type *T = gsl_min_fminimizer_brent;
+  int    status = GSL_CONTINUE; 
+  const  gsl_min_fminimizer_type *T = gsl_min_fminimizer_brent;
   gsl_min_fminimizer *s = gsl_min_fminimizer_alloc(T);
   gsl_min_fminimizer_set(s, &func, x, min_p, max_p);
 
diff --git a/ex-6/main.c b/ex-6/main.c
index ea2da25..a204cc8 100644
--- a/ex-6/main.c
+++ b/ex-6/main.c
@@ -140,17 +140,17 @@ int main(int argc, char **argv) {
     else if (!strcmp(argv[i], "-m")) opts.mode        = argv[++i];
     else if (!strcmp(argv[i], "-n")) opts.noise       = atof(argv[++i]);
     else {
-      fprintf(stderr, "Usage: %s -[cdoebsh]\n", argv[0]);
+      fprintf(stderr, "Usage: %s -[cdoebsrmh]\n", argv[0]);
       fprintf(stderr, "\t-h\t\tShow this message.\n");
       fprintf(stderr, "\t-c\t\tPrint the convolved histogram to stdout.\n");
       fprintf(stderr, "\t-d\t\tAttempt and print the deconvolved histogram.\n");
       fprintf(stderr, "\t-o\t\tPrint the original histogram to stdout.\n");
-      fprintf(stderr, "\t-e N\t\tThe number of events.\n");
-      fprintf(stderr, "\t-b N\t\tThe number of θ bins.\n");
-      fprintf(stderr, "\t-s SIGMA\tThe sigma of gaussian kernel.\n");
-      fprintf(stderr, "\t-r N\t\tThe number of RL deconvolution rounds.\n");
-      fprintf(stderr, "\t-m MODE\t\tThe deconvolution mode: 'fft' or 'rl'.\n");
-      fprintf(stderr, "\t-n MU\t\tThe mean (μ) of Poisson noise to add to the convolution.\n");
+      fprintf(stderr, "\t-e N\t\tThe number of events. (default: 50000)\n");
+      fprintf(stderr, "\t-b N\t\tThe number of θ bins. (default: 150)\n");
+      fprintf(stderr, "\t-s SIGMA\tThe sigma of gaussian kernel.(default: 0.8)\n");
+      fprintf(stderr, "\t-r N\t\tThe number of RL deconvolution rounds. (default: 3)\n");
+      fprintf(stderr, "\t-m MODE\t\tThe deconvolution mode: 'fft' or 'rl'. (default: 'fft')\n");
+      fprintf(stderr, "\t-n MU\t\tThe mean (μ) of Poisson noise to add to the convolution. (default: 0)\n");
       return EXIT_FAILURE;
     }
   }
diff --git a/ex-7/main.c b/ex-7/main.c
index 0a05440..67f146e 100644
--- a/ex-7/main.c
+++ b/ex-7/main.c
@@ -38,11 +38,11 @@ int main(int argc, char **argv) {
       fprintf(stderr, "Usage: %s -[hmisnw]\n", argv[0]);
       fprintf(stderr, "  -h\t\tShow this message.\n");
       fprintf(stderr, "  -m MODE\tThe training mode to use: 'fisher' for \n\t\t"
-                      "Fisher linear discriminant, 'percep' for perceptron.\n");
+                      "Fisher linear discriminant, 'percep' for perceptron. (default: 'fisher')\n");
       fprintf(stderr, "  -i N\t\tThe number of training iterations "
-                       "(for perceptron only).\n");
-      fprintf(stderr, "  -s N\t\tThe number of events in signal class.\n");
-      fprintf(stderr, "  -n N\t\tThe number of events in noise class.\n");
+                       "(for perceptron only). (default: 5)\n");
+      fprintf(stderr, "  -s N\t\tThe number of events in signal class. (default: 800)\n");
+      fprintf(stderr, "  -n N\t\tThe number of events in noise class. (default: 1000)\n");
       fprintf(stderr, "  -w W₁ W₂ B\tSet weights and bias (if pre-trained).\n");
       return EXIT_FAILURE;
     }
diff --git a/notes/todo b/notes/todo
index 19c8072..e69de29 100644
--- a/notes/todo
+++ b/notes/todo
@@ -1,8 +0,0 @@
-- es 1 bootstrap for median
-- es 2
-- es 3
-- rifare es 4
-- es 5
-- es 6
-- es 7
-- scrivere una specie di indice sui programmi (usati dove, linguaggio, --help...)