message: use 'x' to join operator names together
diff: @@ -117,7 +117,8 @@ function getAssemblyOperators(matrices: Matrices, operatorNames: string[][], sta
  }
  // TODO currently using the original operator name for the symmetry operator to be able
  // to link it to the original operator but it might be clearer to introduce an extra field???
  - operators[operators.length] = SymmetryOperator.create(`A-${op.join(',')}`, m);
  + // Operator names are joined together by 'x' to indicate matrix multiplication.
  + operators[operators.length] = SymmetryOperator.create(`A-${op.join('x')}`, m);
  }
  return operators;
  