diff --git a/src/main.rs b/src/main.rs
index 79b9e84..e336b0e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,7 @@ mod truth_table;
 mod ast;
 
 use gray_code::gray_code;
+use truth_table::print_truth_table;
 
 fn main() {
     println!("Hello, world!");
@@ -18,4 +19,5 @@ fn main() {
     println!("{}", gray_code(15));
     println!("{}", gray_code(7));
     println!("{}", gray_code(3));
+    print_truth_table("ZFG|&");
 }
diff --git a/src/truth_table.rs b/src/truth_table.rs
index 3ec29f5..c21fe53 100644
--- a/src/truth_table.rs
+++ b/src/truth_table.rs
@@ -71,7 +71,7 @@ fn recursive_fn(formula: &str, mut vec: Vec<char>, format: String) {
     }
 }
 
-fn print_truth_table(formula: &str) {
+pub fn print_truth_table(formula: &str) {
     let set: HashSet<char> = get_hashset(formula);
     let mut vec: Vec<char> = set.iter().cloned().collect();
     vec.sort();
@@ -87,6 +87,6 @@ fn print_truth_table(formula: &str) {
     separator = format!("{separator}---|");
     println!("{format}");
     println!("{separator}");
-    recursive_fn(formula, vec, String::from("|"));
+    recursive_fn(formula, vec.into_iter().rev().collect(), String::from("|"));
     // call eval formula a lot 
 }
\ No newline at end of file