}
}
-// Now we can write `vec_min`. In order to make it type-check, we have make a deep copy of e.
+// Now we can write `vec_min`. However, in order to make it type-check, we have to make a full (deep) copy of e
+// by calling `clone()`.
fn vec_min(v: &Vec<BigInt>) -> Option<BigInt> {
let mut min: Option<BigInt> = None;
for e in v {