diff --git a/src/Simplex.java b/src/Simplex.java
index b8c0215743e07dc3ddc2e71f7b5bac455503a71b..2dee6e96943499a17521cb3f38d1f905e4c87dda 100644
--- a/src/Simplex.java
+++ b/src/Simplex.java
@@ -61,7 +61,7 @@ public class Simplex {
     int which_phase(){
         int res = -1;
         for (int i = 0; i < x; i++) {
-            if(!signe(matEcart[i][y - 1]))
+            if(signe(matEcart[i][y - 1]))
                 res = i;
         }
         return res;
@@ -78,7 +78,7 @@ public class Simplex {
 
     int getFirstNeg() {
         for (int j = 0; j < this.y; j++) {
-            if(!signe(matEcart[x-1][j])) return j;
+            if(signe(matEcart[x - 1][j])) return j;
         }
         return -1;
     }
@@ -101,7 +101,7 @@ public class Simplex {
             }
         }
         for (int j = 0; j < this.y; j++)
-            if (!signe(this.matEcart[x - 1][j])) {
+            if (signe(this.matEcart[x - 1][j])) {
                 has_neg = true;
             }
         if (has_neg) pivot();
@@ -122,6 +122,6 @@ public class Simplex {
     }
 
     boolean signe(Double x) {
-        return x >= 0;
+        return x < 0;
     }
 }