diff --git a/example/ex-multi03.c b/example/ex-multi03.c
new file mode 100644
index 00000000..a327de4b
--- /dev/null
+++ b/example/ex-multi03.c
@@ -0,0 +1,130 @@
+#include <stdio.h>
+
+#include "m-array.h"
+#include "m-dict.h"
+#include "m-string.h"
+#include "m-variant.h"
+
+/* This is a JSON like syntax, not exactly JSON format */
+
+/* OUT/IN of boolean */
+static inline void boolean_out_str(FILE *f, bool b)
+{
+  fprintf(f, b ? "TRUE" : "FALSE");
+}
+static inline bool boolean_in_str(bool *b, FILE *f)
+{
+  char c = fgetc(f);
+  if (c == 'T') {
+    c = fgetc(f);
+    if (c != 'R') return false;
+    c = fgetc(f);
+    if (c != 'U') return false;
+    c = fgetc(f);
+    return c == 'E';
+  } else if (c == 'F') {
+    c = fgetc(f);
+    if (c != 'A') return false;
+    c = fgetc(f);
+    if (c != 'L') return false;
+    c = fgetc(f);
+    if (c != 'S') return false;
+    c = fgetc(f);
+    return c == 'E';
+  } else {
+    return false;
+  }
+}
+
+/* OUT/IN of float */
+static inline void real_out_str(FILE *f, float r)
+{
+  fprintf(f, "%f", r);
+}
+static inline bool real_in_str(float *r, FILE *f)
+{
+  return fscanf(f, "%f", r) == 1;
+}
+
+/* Header definition */
+
+typedef struct json_node_s *json_t;
+
+extern void json_init (json_t *);
+extern void json_clear (json_t);
+extern void json_init_set (json_t *, json_t);
+extern void json_set (json_t *, json_t);
+extern void json_out_str(FILE *, json_t);
+extern bool json_in_str(json_t *, FILE *);
+
+#define JSON_OPLIST (INIT(json_init M_IPTR), CLEAR(json_clear),         \
+                     INIT_SET(json_init_set M_IPTR), SET(json_set M_IPTR),\
+                     OUT_STR(json_out_str), IN_STR(json_in_str M_IPTR) )
+
+DICT_DEF2(json, string_t, STRING_OPLIST, json_t, JSON_OPLIST)
+
+ARRAY_DEF(json, json_t, JSON_OPLIST)
+
+VARIANT_DEF2(variant_json,
+             (boolean, bool, M_OPEXTEND(M_DEFAULT_OPLIST, OUT_STR(boolean_out_str), IN_STR(boolean_in_str M_IPTR)) ),
+             (real, float, M_OPEXTEND (M_DEFAULT_OPLIST, OUT_STR(real_out_str), IN_STR(real_in_str M_IPTR))),
+             (array, array_json_t, ARRAY_OPLIST(json, JSON_OPLIST)), 
+             (dict, dict_json_t, DICT_OPLIST(json, STRING_OPLIST, JSON_OPLIST)))
+
+struct json_node_s {
+  variant_json_t json;
+};
+
+
+/* Body definition */
+
+void json_new(json_t *p)
+{
+  *p = malloc (sizeof (struct json_node_s));
+  if (*p == NULL) abort();
+}
+
+void json_init(json_t *p)
+{
+  *p = NULL;
+}
+
+void json_clear (json_t p)
+{
+  if (p != NULL) {
+    variant_json_clear (p->json);
+    free(p);
+  }
+}
+
+void json_init_set(json_t *p, json_t o)
+{
+  if (o == NULL) {
+    *p = NULL;
+  } else {
+    json_new(p);
+    variant_json_init_set((*p)->json, o->json);
+  }
+}
+
+void json_set(json_t *p, json_t o)
+{
+  json_clear(*p);
+  json_init_set(p, o);
+}
+
+void json_out_str(FILE *f, json_t o)
+{
+  if (o != NULL) {
+    variant_json_out_str(f, o->json);
+  }
+}
+
+bool json_in_str(json_t *p, FILE *f)
+{
+  if (*p == NULL) {
+    json_new(p);
+    variant_json_init((*p)->json);
+  }
+  return variant_json_in_str((*p)->json, f);
+}