diff --git a/Fragment.glsl b/Fragment.glsl
index a986285..7e6d7a4 100644
--- a/Fragment.glsl
+++ b/Fragment.glsl
@@ -2,19 +2,20 @@
 out vec4 pixColor;
 
 uniform int iterationCount;
+uniform float divergeThreshold;
 
 in vec2 complexPos;
 
-vec2 mul(in vec2 a, in vec2 b) {
-    return vec2(a.x * b.x - a.y * b.y, a.y * b.x + a.x * b.y);
-}
-
 vec3 getColor(in float value){
     vec3 red = vec3(0.5, 0, 0);
     vec3 blue = vec3(0, 0, 0.5);
     return value * red + (1 - value) * blue;
 }
 
+vec2 square(in vec2 c){
+    return vec2(c.x * c.x - c.y * c.y, 2 * c.x * c.y);
+}
+
 void main(){
 
     vec2 z;