diff --git a/src/main.rs b/src/main.rs
index 852db25..f8e24aa 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -39,16 +39,17 @@ fn points_under_graph(
 fn get_sup(
     integral: &Integral<f64>
 ) -> f64 {
-    let multiplier = 1000.0;
     let b = &integral.bounds;
     let f = &integral.function;
     
     let mut sup = f(b.start);
+
+    // needed to iterate over a float range with some step
+    let multiplier = 1000.0;
+    let start_int = (b.start * multiplier) as i64;
+    let end_it = (b.end * multiplier) as i64;
     
-    for i in 
-        (((b.start * multiplier) as i64)..((b.end * multiplier) as i64))
-            .map(|x| (x as f64) / multiplier)
-    {
+    for i in (start_int..end_it).map(|x| (x as f64) / multiplier) {
         let y = f(i);
         // for the π approximation f(-1) and f(1)
         // returned ∞, this if fixes that