diff --git a/cv4/program.c b/cv4/program.c
index e69de29..772c97b 100644
--- a/cv4/program.c
+++ b/cv4/program.c
@@ -0,0 +1,80 @@
+#include "list_ops.h"
+#include <stdlib.h>
+#include <stdbool.h>
+
+list_t *new_list(size_t length, list_element_t elements[]) {
+    list_t *list = malloc(sizeof(list_t) + length * sizeof(list_element_t));
+    list->length = length;
+    for (size_t i = 0; i < length; i++) {
+        list->elements[i] = elements[i];
+    }
+    return list;
+}
+
+list_t *append_list(list_t *list1, list_t *list2) {
+    size_t new_length = list1->length + list2->length;
+    list_t *new_list = malloc(sizeof(list_t) + new_length * sizeof(list_element_t));
+    new_list->length = new_length;
+    for (size_t i = 0; i < list1->length; i++) {
+        new_list->elements[i] = list1->elements[i];
+    }
+    for (size_t i = 0; i < list2->length; i++) {
+        new_list->elements[list1->length + i] = list2->elements[i];
+    }
+    return new_list;
+}
+
+list_t *filter_list(list_t *list, bool (*filter)(list_element_t)) {
+    list_t *temp_list = malloc(sizeof(list_t) + list->length * sizeof(list_element_t));
+    temp_list->length = 0;
+    for (size_t i = 0; i < list->length; i++) {
+        if (filter(list->elements[i])) {
+            temp_list->elements[temp_list->length++] = list->elements[i];
+        }
+    }
+    list_t *filtered_list = new_list(temp_list->length, temp_list->elements);
+    free(temp_list);
+    return filtered_list;
+}
+
+size_t length_list(list_t *list) {
+    return list->length;
+}
+
+list_t *map_list(list_t *list, list_element_t (*map)(list_element_t)) {
+    list_t *mapped_list = malloc(sizeof(list_t) + list->length * sizeof(list_element_t));
+    mapped_list->length = list->length;
+    for (size_t i = 0; i < list->length; i++) {
+        mapped_list->elements[i] = map(list->elements[i]);
+    }
+    return mapped_list;
+}
+
+list_element_t foldl_list(list_t *list, list_element_t initial, list_element_t (*foldl)(list_element_t, list_element_t)) {
+    list_element_t accumulator = initial;
+    for (size_t i = 0; i < list->length; i++) {
+        accumulator = foldl(list->elements[i], accumulator);
+    }
+    return accumulator;
+}
+
+list_element_t foldr_list(list_t *list, list_element_t initial, list_element_t (*foldr)(list_element_t, list_element_t)) {
+    list_element_t accumulator = initial;
+    for (int i = list->length - 1; i >= 0; i--) {
+        accumulator = foldr(list->elements[i], accumulator);
+    }
+    return accumulator;
+}
+
+list_t *reverse_list(list_t *list) {
+    list_t *reversed_list = malloc(sizeof(list_t) + list->length * sizeof(list_element_t));
+    reversed_list->length = list->length;
+    for (size_t i = 0; i < list->length; i++) {
+        reversed_list->elements[i] = list->elements[list->length - 1 - i];
+    }
+    return reversed_list;
+}
+
+void delete_list(list_t *list) {
+    free(list);
+}