diff --git a/example/ex11-algo05.c b/example/ex11-algo05.c
new file mode 100644
index 00000000..a3edd67b
--- /dev/null
+++ b/example/ex11-algo05.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include "m-array.h"
+#include "m-algo.h"
+#include "m-string.h"
+
+ARRAY_DEF(array_int, int)
+#define M_OPL_array_int_t() ARRAY_OPLIST(array_int, M_BASIC_OPLIST)
+ALGO_DEF(array_int, array_int_t)
+
+static bool callback1(int *out, int in, void *data)
+{
+  int *cpt = data;
+  bool ret = true;
+  if (*cpt == -1 && in == 11)
+    *cpt = 0;                               // Start when first reach 11
+  ret &= (*cpt >= 0);                       // Skip initial numbers unequal 11
+  ret &= (in % 2 != 0);                     // Collect odd numbers
+  (*cpt) += ret;
+  ret &= (*cpt <= 5);                      //  Only take five numbers
+  *out = in * in;                           // Square each number
+  return ret;
+}
+
+static void callback_add_int(int *out, int in)
+{
+  *out += in;
+}
+
+static void demo(void)
+{
+  M_LET( (t, M_SEQ(0, 30)), vector, array_int_t) {
+    printf("t=");  array_int_out_str(stdout, t);
+    int b = -1;
+    array_int_transform(vector, t, callback1, &b);
+    printf("\nvector=");  array_int_out_str(stdout, vector); printf("\n");
+    array_int_reduce(&b, vector, callback_add_int);
+    printf("Sum=%d\n", b);
+  }
+}
+
+ARRAY_DEF(array_str, string_t)
+#define M_OPL_array_str_t() ARRAY_OPLIST(array_str, M_STRING_OPLIST)
+ALGO_DEF(array_str, array_str_t)
+
+static bool callback2(string_t *out, const string_t in, void *data)
+{
+  char *cp = data, c = *cp;
+  if (string_search_char(in, c) == M_STRING_FAILURE)
+    return false;
+  string_set(*out, in);
+  return true;
+}
+
+static void demo_split(void)
+{
+  M_LET( (s, ("This is a sentence in C11.")), string_t)
+    M_LET(words, f_words, array_str_t) {
+    array_str_split(words, s, ' ');
+    array_str_transform(f_words, words, callback2, &(char){'i'});
+    printf("f_words="); array_str_out_str(stdout, f_words); printf("\n");
+  }
+}
+
+int main(void)
+{
+  demo();
+  demo_split();
+  return 0;
+}