feat: add mmultiscripts prescript default case

src/converters/mathml-interfaces-to-latex/mathml-tag-to-latex/mathml-tags/MMultiscripts.ts

@@ -8,7 +8,7 @@ export class MMultiscripts extends MathMLTag {
   }
 
   convert(): string {
-    if (this._children.length < 3) throw new InvalidNumberOfChild(this.name, 2, this._children.length, 'at least');
+    if (this._children.length < 3) throw new InvalidNumberOfChild(this.name, 3, this._children.length, 'at least');
 
     const base = this._children[0];
     const sub = this._children[1];
@@ -20,7 +20,29 @@ export class MMultiscripts extends MathMLTag {
     const wrappedSub = new BracketWrapper().wrap(sub.convert());
     const wrappedSup = new BracketWrapper().wrap(sup.convert());
 
-    return `${this._wrapInParenthesisIfThereIsSpace(base.convert())}_${wrappedSub}^${wrappedSup}`;
+    return this._prescriptLatex() + this._wrapInParenthesisIfThereIsSpace(base.convert()) + this._postscriptLatex();
+  }
+
+  private _prescriptLatex(): string {
+    if (this._children[3]?.name !== 'mprescripts') return '';
+
+    const sub = this._children[4];
+    const sup = this._children[5];
+
+    const subLatex = sub ? sub.convert() : '';
+    const supLatex = sup ? sup.convert() : '';
+
+    return `\\_{${subLatex}}^{${supLatex}}`;
+  }
+
+  private _postscriptLatex(): string {
+    const sub = this._children[1];
+    const sup = this._children[2];
+
+    const subLatex = sub ? sub.convert() : '';
+    const supLatex = sup ? sup.convert() : '';
+
+    return `_{${subLatex}}^{${supLatex}}`;
   }
 
   private _wrapInParenthesisIfThereIsSpace(str: string): string {