diff --git a/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.c b/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.c
index 0e0754f..2c95bce 100644
--- a/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.c
+++ b/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.c
@@ -1,63 +1,324 @@
 #include "dlist.h"
 
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 struct dlist *dlist_init(void)
 {
-    // TODO
-    return NULL;
+    struct dlist *dlist = malloc(sizeof(struct dlist));
+    if(!dlist) return NULL;
+    dlist->size = 0;
+    dlist->head = NULL;
+    dlist->tail = NULL;
+    return dlist;
 }
 
 void dlist_clear(struct dlist *list)
 {
+    if(!list) return;
 
+    struct node *tmp = list->head;
+    struct node *next;
+
+    while(tmp != NULL){
+        next = tmp->next;
+        free(tmp);
+        tmp = next;
+    }
+    free(list);
 }
 
 size_t dlist_length(struct dlist *l)
 {
-    // TODO
-    return 0;
+    if(!l) return 0;
+
+    size_t count = 0;
+    struct node *tmp = l->head;
+    while(tmp != NULL){
+        count ++;
+        tmp = tmp->next;
+    }
+    return count;
 }
 
 void dlist_push_front(struct dlist *l, int data)
 {
-    // TODO
+    if(!l) return;
+
+    struct node *node = malloc(sizeof(struct node));
+    if(!node) return;
+
+    node->data = data;
+    node->prev = NULL;
+    
+    if(l->head == NULL){
+        node->next = NULL;
+        //l->head = node;
+        l->tail = node;
+    }
+    else{
+        node->next = l->head;
+        l->head->prev = node;
+        //l->head = node;
+    }
+
+    l->head = node;
+    l->size ++;
 }
 
 void dlist_push_back(struct dlist *l, int data)
 {
-    // TODO
+    if(!l)return;
+    struct node *node = malloc(sizeof(struct node));
+    if(!node) return;
+
+    node->data = data;
+    node->next = NULL;
+
+    if(l->head == NULL){
+        node->prev = NULL;
+        l->head = node;    
+
+    }
+    else{
+        node->prev = l->tail;
+        l->tail->next = node;
+    }
+
+    l->tail = node;
+    l->size ++;
+
+
 }
 
 void dlist_remove(struct dlist *list, int data)
 {
-    // TODO
+      if(!list || !list->head)return;
+
+      struct node *tmp = list->head;
+      //struct node *next;
+
+      while(tmp != NULL && tmp->data != data){
+        tmp = tmp->next;
+      }
+
+      if(tmp == NULL) return;
+
+      if(tmp->prev != NULL) tmp->prev->next = tmp->next;
+      else list->head = tmp->next;
+
+      if(tmp->next != NULL)tmp->next->prev = tmp->prev;
+      else list->tail = tmp->prev;
+
+
+      //if(tmp->next == NULL && tmp->data != data) return;
+
+      //if(tmp->data == data && tmp->next == NULL){
+      //  tmp->prev->next = NULL;  
+       // free(tmp);
+        //return;
+      //}
+      //tmp->next->prev = tmp->prev;
+      //tmp->prev->next = tmp->next;
+      list->size --;
+      free(tmp);
+
 }
 
 struct dlist *dlist_from_str(char *str)
 {
-    // TODO
-    return NULL;
+    if(!str) return dlist_init();
+    
+    struct dlist *dlist = dlist_init();
+
+
+    size_t len = strlen(str);
+    size_t index = 0;
+    for(size_t i = 0; i < len; i ++){
+        
+        if(str[i] == '+' || str[i] == '-'){
+            char s = str[i];
+            i ++;
+            
+            if(i >= len) break;
+
+            int value = atoi(&str[i]);
+
+            if(s == '+') dlist_push_back(dlist, value);
+            else dlist_remove(dlist, value);
+            index = i;
+
+            while(i < len && str[index] >= '0' && str[index] <= '9'){
+                if(i + 1 < len && str[index + 1] >= '0' && str[index + 1] <= '9') index ++;
+                else break;
+            }                           
+        }
+    }
+
+    return dlist;
 }
 
 struct node *dlist_find(struct dlist *list, int data)
 {
-    // TODO
+    if(!list) return NULL;
+
+    struct node *tmp = list->head;
+
+    while(tmp->next != NULL && tmp->data != data){
+        tmp = tmp->next;
+    }
+
+    if(tmp->data == data) return tmp;
+
     return NULL;
 }
-
+/*
 void dlist_print(struct dlist *l)
 {
-    // TODO
+  
 }
+*/
 
 void dlist_concat(struct dlist *l1, struct dlist *l2)
 {
-    // TODO
+    if(!l1) return ;
+    if(!l2) return ;
+    if (!l1 && !l2) return ;
+    
+    struct node *tmp = l2->head;
+    for (size_t i = 0; i < l2->size; i ++){
+      dlist_push_back(l1, tmp->data);
+      tmp = tmp->next;
+    }
+
+    dlist_clear(l2);
 }
 
 void dlist_insert(struct dlist *l, int data, int i)
 {
-    // TODO
+    if(!l) return ;
+    size_t o = i;
+    if(o > l->size) return;
+    
+    if(i == 0) dlist_push_front(l, data);
+    else if (o == l->size) dlist_push_back(l, data);
+    else{
+        
+        struct node *tmp = l->head;
+        
+        for(size_t z = 0; z < o; z ++){
+            tmp = tmp->next;
+        }
+    struct node *node = malloc(sizeof(struct node));
+    if(!node)return;
+    node->data = data;
+    
+    node->next = tmp;
+    node->prev = tmp->prev;
+    if(tmp->prev) tmp->prev->next = node;
+    tmp->prev = node;
+    
+    
+    l->size ++;
+    }
 }
+/*
+int main(){
+struct dlist *l = dlist_init();
+printf("length = %zu\n", l->size); // 0
+printf("head = %p\n", (void *)l->head); // (nil) or NULL
+printf("tail = %p\n", (void *)l->tail); // (nil) or NULL
+dlist_clear(l);
+// l is now invalid
+
+
+    struct dlist *l = dlist_init();
+size_t len = dlist_length(l);
+printf("Length: %zu\n", len); // 0
+dlist_clear(l);
+
+
+    struct dlist *l = dlist_init(); // l: NULL
+dlist_push_front(l, 10);              // l: 10 -> NULL
+printf("%i\n",l->head->data);
+dlist_push_front(l, 20);              // l: 20 -> 10 -> NULL
+dlist_clear(l);
+
+
+    struct dlist *l = dlist_init();
+dlist_push_back(l, 10); // l: 10 -> NULL
+printf("%i\n", l->tail->data);
+dlist_push_back(l, 20); // l: 10 -> 20 -> NULL
+printf("%i\n", l->tail->data);
+dlist_clear(l);
+
+    struct dlist *l = dlist_init();
+dlist_push_back(l, 1);
+dlist_push_back(l, 2);
+dlist_push_back(l, 3);
+dlist_push_back(l, 2);
+                        // l: 1 -> 2 -> 3 -> 2 -> NULL
+dlist_remove(l, 2);      // l: 1 -> 3 -> 2 -> NULL
+dlist_remove(l, 2);      // l: 1 -> 3 -> NULL
+dlist_remove(l, 2);      // l: 1 -> 3 -> NULL
+printf("%i -> %i\n", l->head->data, l->tail->data);
+dlist_clear(l);
+
+
+    dlist_from_str("+2+10+42+2+223-2"); // NULL<->10<->42<->2<->223<->NULL
+dlist_from_str("-2+10+42+2+223-2"); // NULL<->10<->42<->223<->NULL
+dlist_from_str(""); // Return an empty list (size = 0, head = NULL, tail = NULL)
+dlist_from_str("-2-10-42-2-223"); // Return an empty list too
+
+
+    struct dlist *l = dlist_init();
+dlist_push_back(l, 1);
+dlist_push_back(l, 2);
+dlist_push_back(l, 3);
+dlist_push_back(l, 2);
+                            // l: 1 -> 2 -> 3 -> 2 -> NULL
+struct node *n;
+n = dlist_find(l, 1);        // n->data == 1
+printf("%i\n", n->data);
+n = dlist_find(l, 3);        // n->data == 3
+n = dlist_find(l, 223);      // n == NULL
+dlist_clear(l);
+
+
+    struct dlist *l1 = dlist_init();
+for (int i = 0 ; i < 5 ; i++)
+    dlist_push_back(l1, i);
+struct dlist *l2 = dlist_init();
+for (int i = 0 ; i < 5 ; i++)
+    dlist_push_front(l2, i);
+                                          // l1: 0 <-> 1 <-> 2 <-> 3 <-> 4 <-> NULL
+                                          // l2: 4 <-> 3 <-> 2 <-> 1 <-> 0 <-> NULL
+dlist_concat(l1, l2);                      // l1: 0 <-> 1 <-> 2 <-> 3 <-> 4 <-> 4 <-> 3 <-> 2 <-> 1 <-> 0 <-> NULL
+                                          // l1->size = 10
+struct node *tmp = l1->head;
+for(size_t i = 0; i < l1->size; i ++){
+    printf("%i - ", tmp->data);
+    tmp = tmp->next;
+}
+free(tmp);
+dlist_clear(l1); // If you freed correctly, no memory leaks should be displayed on your terminal
+
+struct dlist *l = dlist_init();
+for (int i = 0 ; i < 5 ; i++)
+    dlist_push_back(l, i);
+                                          // l: 0 <-> 1 <-> 2 <-> 3 <-> 4 <-> NULL
+dlist_insert(l, -4, 0);                    // l: -4 <-> 0 <-> 1 <-> 2 <-> 3 <-> 4 <-> NULL
+dlist_insert(l, 5, 6);                     // l: -4 <-> 0 <-> 1 <-> 2 <-> 3 <-> 4 <-> 5 <-> NULL
+dlist_insert(l, 5, 12);                    // l: -4 <-> 0 <-> 1 <-> 2 <-> 3 <-> 4 <-> 5 <-> NULL
+struct node *tmp = l->head;
+for(size_t i = 0; i < l->size; i ++){
+    printf("%i - ", tmp->data);
+    tmp = tmp->next;
+}
+dlist_clear(l);
+
+
+
+}*/
diff --git a/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.h b/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.h
index e69de29..dc49ded 100644
--- a/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.h
+++ b/RecapThoseAnimals/Fundamentals/double_linked_list/dlist.h
@@ -0,0 +1,28 @@
+#ifndef DLIST_H
+#define DLIST_H
+#include <stdio.h>
+struct node{
+    int data;
+    struct node *next;
+    struct node *prev;
+};
+
+struct dlist{
+    size_t size;
+    struct node *head;
+    struct node *tail;
+};
+
+struct dlist *dlist_init(void);
+void dlist_clear(struct dlist *list);
+size_t dlist_length(struct dlist *l);
+void dlist_push_front(struct dlist *l, int data);
+void dlist_push_back(struct dlist *l, int data);
+void dlist_remove(struct dlist *list, int data);
+struct dlist *dlist_from_str(char *str);
+struct node *dlist_find(struct dlist *list, int data);
+void dlist_concat(struct dlist *l1, struct dlist *l2);
+void dlist_insert(struct dlist *l, int data, int i);
+
+
+#endif
diff --git a/RecapThoseAnimals/Fundamentals/process/fork.c b/RecapThoseAnimals/Fundamentals/process/fork.c
index 1cdb5b2..77b20da 100644
--- a/RecapThoseAnimals/Fundamentals/process/fork.c
+++ b/RecapThoseAnimals/Fundamentals/process/fork.c
@@ -1,6 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ -8,12 +9,44 @@
 
 int is_prime(size_t n)
 {
-    // TODO
-    return 0;
-}
 
+
+
+    int status;
+    pid_t pid = fork();
+    if(pid < 0) return -1;
+    //Child
+    if(pid == 0){
+        for(size_t i = 2; i < n; i ++){
+            if(n % i == 0 && i != n){
+                printf("Child speaking: my number %zu is not a prime number\n", n);
+                printf("We both say hi!\n");
+                exit(0);
+            }
+        }
+        printf("Child speaking: my number %zu is a prime number\n", n);  
+        printf("We both say hi!\n");
+        exit(1);
+    }
+    
+    //daddy milk
+    else{
+        if(waitpid(pid, &status, 0) == -1) return -1;
+
+        if(WIFEXITED(status)){
+            if(WEXITSTATUS(status) == 1) printf("Parent speaking: stop wasting my time of course %zu is a prime number\n", n);
+            else printf("Parent speaking: stop wasting my time of course %zu is not a prime number\n", n);
+        }
+        printf("We both say hi!\n");
+    }
+    
+
+
+    return WEXITSTATUS(status);
+}
+/*
 int salute(int num_guests, char *guests[])
 {
-    // TODO
+    
     return 0;
-}
+}*/
diff --git a/RecapThoseAnimals/Fundamentals/process/main.c b/RecapThoseAnimals/Fundamentals/process/main.c
index 73f9376..a259798 100644
--- a/RecapThoseAnimals/Fundamentals/process/main.c
+++ b/RecapThoseAnimals/Fundamentals/process/main.c
@@ -15,6 +15,7 @@ int main(int argc, char *argv[])
             is_prime(atoi(argv[i]));
         }
     }
+    /*
     else if (!strcmp(argv[0], "./salute"))
     {
         return salute(argc, argv);
@@ -23,6 +24,6 @@ int main(int argc, char *argv[])
     {
         printf("No such thing as %s\n", argv[0]);
     }
-
+*/
     return 0;
 }