If company E is worth say, 70M, and has a 70% stake in a joint...

If company E is worth say, 70M, and has a 70% stake in a joint venture or ventures, then it stands to reason that the market values the venture(s) at 100M.
ie...Company M's share of said ventures (30%) is worth 30% of the venture value...30M.
If company M also owns 1/3 of E's shares as well then add 1/3 of 70M to the figure.

I have checked my figures and logic several times and yes, at the risk of sounding arrogant I do believe the market hasn't "got it" yet....some on this forum have, and long before I posted about it...
I simply tried to spell it out for the board in a more conversational manner.

I put this value anomaly down to the differing marketing presence of the two companies...and while it's important to get the message out the market usually assigns true and fair value over time.
I do not understand your "double dipping" statement.
Why is having a share of the JV and a share of the other partner "double-dipping"??

For goodness sake...Mxr is surely the parent company that "spun off" ERO....do you think they would give those tenements and rights away?
No...the deal is they effectively hold 1/2 of them, and are free carried for a while as well.
Which is perfectly normal and acceptable.

If you don't see the extra value in MXR, fine...stick with ERO.
But to me it looks like the chance to buy the same thing at half price, and I happen to like bargains.