docs: function formula2d3 (formulaParsed) {
    // const formulaParsed = bolFormulaParser.parse(formulaString);
    let node = {};
    if (!formulaParsed.relation && !formulaParsed.negation && !formulaParsed.junctor) {
      throw new Error("formula2d3 called with bad imput");
    }
    if (formulaParsed.relation) {
      node.content = formulaParsed.relation;
      // node.children = atomTerms(formulaParsed);
      node.children = []; // atomTerms(formulaParsed);
    }
    if (formulaParsed.negation) {
      node.content = formulaParsed.negation;
      node.children = [formula2d3(formulaParsed.content)];
    }
    if (formulaParsed.junctor) {
      node.content = formulaParsed.junctor;
      node.children = [formula2d3(formulaParsed.left), formula2d3(formulaParsed.right)];
    }
    // if (formulaParsed.quantifier) {
    //   node.content = formulaParsed.quantifier;
    //   node.children = [nodeOfTerm(formulaParsed.variable), formula2d3(formulaParsed.formula)];
    // }
    // if (formulaParsed.guard) {
    //   node.content = "&";
    //   node.children = [
    //     formula2d3(formulaParsed.guard),
    //     {content: "~", children: [formula2d3(formulaParsed.formula)]}
    //   ];
    // }
    return node;
  }