src/Formulas/FormulasResults.php
public function isValid(FormulasInterface $formula): bool
    {
        $result = $formula->getResult();

        if ((is_array($result) && count($result) > 0) || is_numeric($result)) {
            return true;
        }

        return false;
    }
public function isValid(FormulasInterface $formula): bool
    {
        $result = $formula->getResult();

        if ((is_array($result) && count($result) > 0) || is_numeric($result)) {
            return true;
        }

        return false;
    }
Validates the formula by validating the result
A formula is not valid if the result is : null, an empty array or not a float
@param FormulasInterface $formula
@return bool