# 3.3. Step - 02 : Run with undefined steps¶

As of now, we only have the test specifications as defined earlier.

```
# features/sample-addition.feature
Feature: Simple Addition
Showcase simple addition for the BDD Book.
Scenario: Addition of single digit numbers
Given I have '1' and '3'
When I add them
Then The result must be '4'
Scenario: Addition of double digit numbers
Given I have '70' and '29'
When I add them
Then The result must be '99'
```

When we run `behave`

, it would have nothing to test actually, *but still let’s run it*:

```
behave --no-timings --no-source
```

As you can see, it has already tried to run few tests, but shows that few have filed, and we have undefined steps.

```
Feature: Simple Addition
Showcase simple addition for the BDD Book.
Scenario: Addition of single digit numbers
Given I have '1' and '3'
When I add them
Then The result must be '4'
Scenario: Addition of double digit numbers
Given I have '70' and '29'
When I add them
Then The result must be '99'
Failing scenarios:
features/simple-addition.feature:7 Addition of single digit numbers
features/simple-addition.feature:12 Addition of double digit numbers
0 features passed, 1 failed, 0 skipped
0 scenarios passed, 2 failed, 0 skipped
0 steps passed, 0 failed, 0 skipped, 6 undefined
Took 0m0.000s
```

And it also gives us some kind of hint what we have to do and what is missing:

```
You can implement step definitions for undefined steps with these snippets:
@given(u'I have \'1\' and \'3\'')
def step_impl(context):
raise NotImplementedError(u'STEP: Given I have \'1\' and \'3\'')
@when(u'I add them')
def step_impl(context):
raise NotImplementedError(u'STEP: When I add them')
@then(u'The result must be \'4\'')
def step_impl(context):
raise NotImplementedError(u'STEP: Then The result must be \'4\'')
@given(u'I have \'70\' and \'29\'')
def step_impl(context):
raise NotImplementedError(u'STEP: Given I have \'70\' and \'29\'')
@then(u'The result must be \'99\'')
def step_impl(context):
raise NotImplementedError(u'STEP: Then The result must be \'99\'')
```