diff --git a/src/dichotomie.ts b/src/dichotomie.ts
index 115d1f6b0afb84c288dbbc5278f15e2bd98cc8d4..e748417c9db1e3c3087721f151f988710ecdbbeb 100644
--- a/src/dichotomie.ts
+++ b/src/dichotomie.ts
@@ -37,6 +37,11 @@ export class Dichotomie extends Debug {
 
     private _func: () => number;
 
+    /**
+     * si > 0, un calcul dichotomique est en cours
+     */
+    private static _inDicho: number = 0;
+
     /**
      * Construction de la classe.
      * @param nub Noeud de calcul contenant la méthode de calcul Equation
@@ -68,6 +73,10 @@ export class Dichotomie extends Debug {
         this._startIntervalMaxSteps = n;
     }
 
+    public static get inDico(): boolean {
+        return Dichotomie._inDicho > 0;
+    }
+
     public CalculX(x: number): number {
         this.vX = x;
         return this.Calcul();
@@ -80,6 +89,8 @@ export class Dichotomie extends Debug {
      * @param rInit valeur initiale approximative de x
      */
     public Dichotomie(rTarget: number, rTol: number, rInit: number): Result {
+        Dichotomie._inDicho++;
+
         this._target = rTarget;
         // console.log("-----");
         // for (let x = 0; x <= 1; x += 0.1)
@@ -109,20 +120,24 @@ export class Dichotomie extends Debug {
                     this.debug(
                         `${this.analyticalSymbol}(${this.sVarCalc}=${s.value}) = ${rTarget}`
                     );
+                    Dichotomie._inDicho--;
                     return new Result(s.value);
                 } else {
                     this.debug(
                         "Non convergence"
                     );
+                    Dichotomie._inDicho--;
                     return new Result(new Message(MessageCode.ERROR_DICHO_CONVERGE, {
                         lastApproximation: s.value
                     }), this.nub);
                 }
             } else {
+                Dichotomie._inDicho--;
                 return new Result(r.res);
             }
         } catch (e) {
             // un appel à Calcul() a généré une erreur
+            Dichotomie._inDicho--;
             return this.nub.result;
         }
     }