diff --git a/src/base.ts b/src/base.ts
index 27737d11ca0dac34dfb7f728e138910d52c1a5e8..dfbaf9bdef475ee0e43eb3a35f5d68f945a4a99a 100644
--- a/src/base.ts
+++ b/src/base.ts
@@ -106,3 +106,7 @@ export function floatDivAndMod(a: number, b: number, e: number = 1E-7): { q: num
     }
     return { q, r };
 }
+
+export function capitalize(s: string): string {
+    return s.charAt(0).toUpperCase() + s.slice(1);
+}
diff --git a/src/macrorugo/macrorugo_compound.ts b/src/macrorugo/macrorugo_compound.ts
index 19b42e56cb36666fa04e7088d40283956d0d4cb1..39252ee23cae1e329260f45f57d16e3341f996d1 100644
--- a/src/macrorugo/macrorugo_compound.ts
+++ b/src/macrorugo/macrorugo_compound.ts
@@ -24,6 +24,7 @@ export class MacrorugoCompound extends MacroRugo implements Observer {
         this._calcType = CalculatorType.MacroRugoCompound;
         this._props.addObserver(this);
         this.properties.setPropValue("inclinedApron", false);
+        this._childrenType = "MacroRugo";
     }
 
     /**
diff --git a/src/nub.ts b/src/nub.ts
index 958f3763d824546875a904668400cf6b7069f066..720858153602971900c1235e1527bab1ff3ff561 100644
--- a/src/nub.ts
+++ b/src/nub.ts
@@ -17,6 +17,13 @@ import { ResultElement } from "./util/resultelement";
  */
 export abstract class Nub extends ComputeNode implements IObservable {
 
+    /** type of children elements, used by GUI for translation */
+    protected _childrenType: string = "";
+
+    public get childrenType(): string {
+        return this._childrenType;
+    }
+
     public get result(): Result {
         return this._result;
     }
diff --git a/src/structure/parallel_structure.ts b/src/structure/parallel_structure.ts
index 107b5b571a63ba2f13b20e3f6f2117c9460d176a..f42fee6c4b253dd73a42f8b4ac5fdc487f775952 100644
--- a/src/structure/parallel_structure.ts
+++ b/src/structure/parallel_structure.ts
@@ -21,6 +21,7 @@ export class ParallelStructure extends Nub {
     constructor(prms: ParamsEquation, dbg: boolean = false) {
         super(prms, dbg);
         this._calcType = CalculatorType.ParallelStructure;
+        this._childrenType = "Structure";
     }
 
     /** children casting */