diff --git a/src/prob4/mod.rs b/src/prob4/mod.rs
index 491afa2..35e3b3e 100644
--- a/src/prob4/mod.rs
+++ b/src/prob4/mod.rs
@@ -4,7 +4,9 @@ pub fn mutual_inclusion(first_pair: &[u32], second_pair: &[u32]) -> bool {
 }
 
 pub fn complete_overlap(first_pair: &[u32], second_pair: &[u32]) -> bool {
-    (second_pair[0] <= first_pair[0] && first_pair[0] <= second_pair[1]) || (second_pair[0] <= first_pair[1] && first_pair[1] <= second_pair[1])
+    first_pair[0] >= second_pair[0] && first_pair[0] <= second_pair[1]
+        || first_pair[1] >= second_pair[0] && first_pair[1] <= second_pair[1]
+        || mutual_inclusion(first_pair, second_pair)
 }
 
 pub fn solve(file_path: &str, unary_operator: &dyn Fn(&[u32], &[u32]) -> bool) -> i32 {