I should be more clear.  The 2 options in the case below is

1) Numpy License Headers Only

2) Apache Header with Numpy License Header

Re-reading my original reply does sound like I'm saying the Numpy license should be removed in the case for the Apache License Headers from the file.  This was not my intent.  John states it more clearly in his reply that removal of the Numpy License requires additional steps.

- Bob

On 6/15/2020 3:05 AM, Chen, Ciyong wrote:
Hi Bob, Leonard,

Thanks for the elaboration/guideline on the dual license issue.
May I have the conclusion as below based on Bob’s direction/suggestion:

  *   If there’s no any different opinion or objection,  keep either origin Numpy license or ASF license but not dual, which depends on how MXNet’s source file evolves when the origin Numpy files changes? And the PPMC has all the authority to change the file like removing the additional license if needed.

Please correct me if I mis-understand anything, and help to determine the best appropriate way to handle such case. Thanks!

Best Regards,

From: Bob Paulin <bob@bobpaulin.com>
Sent: Sunday, June 14, 2020 2:20 AM
To: lausen@apache.org; dev@mxnet.apache.org; general@incubator.apache.org
Subject: [DISCUSS] When to add Apache Headers to Third Party Code [WAS] Re: [MENTORS] PPMC case-by-case decision for major modifications of third-party work guidance


I agree there does not appear to be consensus on when it's appropriate to add Apache License Headers to Third Party code across projects.  Here is Justin's email that request the Apache Headers removed [1]


- file copyright  NumPy Developers [6] this file look to incorrectly have an ASF header on it


6. ./src/operator/numpy/np_einsum_path_op-inl.h


We want to make the choice that will be most sustainable for the project and most correct for the situation.

Based on the emails I linked in the prior email it does seem like the cases where dual headers are appropriate is when there are Major Modifications.  In the case of


The file is derived from the implementation in Numpy [2].  If the implementation in Numpy changes will this file change?  If so then the community will be tasked with continuing to re-port the changes over that is always based on Numpy so it may be more appropriate to just keep the Numpy license.

Will MXNet likely evolve this file in a way that it's no longer resembles the Numpy implementation (Major Modification)?  If so it may be better to keep the Apache Header as going forward the file will represent the work of the MXNet community not that of Numpy.

Hopefully the above helps clarify my perspective on how to determine case by case.  I don't see the dual license state as the simpler case in all situations.  I don't believe you would have to get the original committer to relicense the file to you in order to remove the additional license.  I believe the PPMC has all the authority it needs to change the file.  I'd be interested to hear if this is a position that the rest of the Mentors/Incubator agree with.  I know Hen has been involved in some of the conversations in support of dual licenses.  Has this ever required escalation to an actual Lawyer in Legal?  Or have these determinations been low enough risk that we are comfortable with our PMC making best effort decisions based on the ASF guidelines?

- Bob

[1] https://lists.apache.org/thread.html/rb83ff64bdac464df2f0cf2fe8fb4c6b9d3b8fa62b645763dc606045f%40%3Cgeneral.incubator.apache.org%3E

[2] https://github.com/numpy/numpy/blob/master/numpy/core/einsumfunc.py
On 6/12/2020 7:20 PM, Leonard Lausen wrote:

Thank you Bob for the elaboration. PPMC would like to minimize complexity,

that's why we ask for your recommendation.

If it's easiest to just keep the original license header, we can do that. Do we

need the contributor to re-license their contribution, or is the contribution

already available under both licenses as both license headers were included by

the contributor and the ASF header can simply be deleted?

Reading through the threads you referenced, there does not seem to be a strong

consensus in the ASF about how to handle this situation. For example, quoting

Roman Shaposhnik [2] in support of just putting 2 License Headers for


Hm. This is tricky, now that I re-read the language of the ASF license

header I'm not sure anymore. I *think* the language there should allow

you to slap said header on a compatible license code.

Besides, the alternative is much messier: every time somebody touches

that file he/she needs to decide whether it is time for an ASF header

or not.

I *think* (but I'd love for old-timers to chime in and correct me) that #3-5

were written from though-shall-not-fork-communities perspective.

Can we follow this approach (keep 2 License headers) for simplicity (assuming

removal of ASF header will require extra steps)?

With respect to einsumfunc.py [5] vs np_einsum_op.cc [6] if this is in

fact a port where the behavior was copied/derived directly from numpy I

could see that as supporting Justin's case that the Apache header should

be removed.  However that is just my opinion.

Which email of Justin are you referring to?

Best regards


[1]: http://www.apache.org/legal/src-headers.html#purpose



On Wed, 2020-06-10 at 21:39 -0500, Bob Paulin wrote:

First general disclaimer: I am not a lawyer.

Second Disclaimer with an engineer hat on we want to avoid copying third

party code into the project since it increases the amount of maintenance

in a sense from a code standpoint and from a licensing standpoint.  If

at all possible it is preferable to either link or try to find a way to

integrate your tweaks back into the other projects before taking on the

burden of housing the code in MXNet.  I do hope these options were

considered or are being looked at for refactoring in the project since

it will help the long term viability of the project.

Now to your question.  Similar situations have been discussed both on

legal [1] and on incubator [2][3].  It may be useful to review some of

these threads to understand how other projects made this determination.

There are instances where other members have stated it is appropriate

and the dual headers have been used [4].  It seems in some of these

cases the PMC has reached out to the other projects to ask for

permission to apply the Apache license.

With respect to einsumfunc.py [5] vs np_einsum_op.cc [6] if this is in

fact a port where the behavior was copied/derived directly from numpy I

could see that as supporting Justin's case that the Apache header should

be removed.  However that is just my opinion.  If the PMC feels strongly

it would make sense to escalate to legal-discuss.   These are case by

case decisions and the more third party code that gets copied in the

more drag there will be on the community to deal with these issues.  I

would also encourage discussion of each case to remain on list so that

the incubator PMC can see how the PPMC is making these determinations.

- Bob







[4] https://github.com/apache/trafodion/blob/master/core/sql/parser/ulexer.h

[5] https://github.com/numpy/numpy/blob/master/numpy/core/einsumfunc.py



On 6/10/2020 5:29 PM, Leonard Lausen wrote:

Hi Bob,

yes, your understanding is correct. To further give an example I'd like to


Haozheng who added two of the files in question:

The two files originate from >

https://github.com/numpy/numpy/blob/master/numpy/core/einsumfunc.py .

I translated them from python to cpp. The original files are subject to


the following license:



Thank you


On Wed, 2020-06-10 at 07:42 -0500, Bob Paulin wrote:


Let me restate to make sure I understand what's being asked.

1) There is third party code in the project that has Major Modifications


the original third party source.

2) The original third party code does not currently have two license


(ex Third Party Code has MIT license only.  Apache License header was


when it was checked into MXNet repo with modifications)

3) You are asking if the files can remain in the MXNet repository with


license headers.

- Bob

On 6/9/2020 5:07 PM, Leonard Lausen wrote:

Hi Mentors,

https://www.apache.org/legal/src-headers.html#3party states the 5 rules


handling third-party code included in the project [1]. In particular



handle major modifications on a case-by-case basis.

But the other rules state

1. Do not modify or remove any copyright notices or licenses within


party works.


2. Do not add the standard Apache License header to the top of third-


source files.

The major modifications in question [2] are currently licensed under


License but the files originate from a third-party and there are thus


license headers in the files. This is in conflict with rule 2.

Could you clarify if rule 2 is not a rule but only a guideline that can


overruled in PPMC's case-by-case decision? What's your recommendation?



we keep the 2 headers in place?

Best regards



0. The term "third-party work" refers to a work not submitted directly



ASF by the copyright owner or owner's agent. This includes parts of a


submitted directly to the ASF for which the submitter is not the


owner or owner's agent.

1. Do not modify or remove any copyright notices or licenses within


party works.

2. Do ensure that every third-party work includes its associated



if that requires adding a copy of the license from the third-party


site into the distribution.

3. Do not add the standard Apache License header to the top of third-


source files.

4. Minor modifications/additions to third-party source files should


be licensed under the same terms as the rest of the rest of the third-


source for convenience.

5. Major modifications/additions to third-party should be dealt with

on a

case-by-case basis by the PMC.