Litipk\BigNumbers\Decimal::exp PHP Method

    public function exp($scale = null)
    {
        if ($this->isZero()) {
            return DecimalConstants::one();
        }
        $scale = $scale === null ? max($this->scale, (int) ($this->isNegative() ? self::innerLog10($this->value, $this->scale, 0) : 16)) : $scale;
        return self::factorialSerie($this, DecimalConstants::one(), function ($i) {
            return DecimalConstants::one();
        }, $scale);
    }