> In assert Integral(x*y*z, (x, 1, 2), (y, 1, 3)).is_number is False, z is left without defining a limit for integration. Other counterparts are not in this form.

Can you find this test:
```python
    assert Integral(x, (y, 1, 2)).is_number is False
```
or I should point you to the line number?  Can you explain the difference with your test?

> In assert Integral(x*y*z, (x, 1, 2), (y, 1, 3), (z, 1, 3)).is_number is True, the remedy to the above test (not the E.g.) is rendered.

I'm asking: **why we need this test**?  We don't have such one?  Are you sure?

> Further I could not see three variables integration which results in an integer (number).

We don't have any test with 100500 variables, which results in an integer...

It's not a problem to have redundant tests, but please take look around and avoid such a situation.