if: even though vs. perhaps not even

[suprunp]

Merriam-Webster's Collegiate Dictionary, 11th Edition

4. : even though : although perhaps
an interesting if untenable argument
5. : and perhaps not even
few if any changes are expected
— often used with not
difficult if not impossible

Can there be an 'overlap' between these two meanings or is it impossible on the whole?
(What I'm trying to say is: [for example] Is it possible to understand the phrase it is difficult if possible either as it is difficult although perhaps it is possible or as it is difficult and perhaps not even possible?

Thanks.

[Hedwig]

Merriam-Webster's Collegiate Dictionary, 11th Edition

4. : even though : although perhaps
an interesting if untenable argument
5. : and perhaps not even
few if any changes are expected
— often used with not
difficult if not impossible

Can there be an 'overlap' between these two meanings or is it impossible on the whole?
(What I'm trying to say is: [for example] Is it possible to understand the phrase it is difficult if possible either as it is difficult although perhaps it is possible or as it is difficult and perhaps not even possible?

Thanks.

Hullo, sup,
I'm not sure I understand the question. Are you asking about the third example, difficult if not impossible, or are you adding a fourth example, difficult if possible?

[suprunp]

Hullo, sup,
I'm not sure I understand the question. Are you asking about the third example, difficult if not impossible, or are you adding a fourth example, difficult if possible?

— often used with not

I surmise from this entry that it is possible to use if in 5th meaning (5. : and perhaps not even) without not [rarely], therefore difficult if not impossible can be paraphrased as difficult if possible.
(But this is only my humble opinion.)

[bhaisahab]

I surmise from this entry that it is possible to use if in 5th meaning (5. : and perhaps not even) without not [rarely], therefore difficult if not impossible can be paraphrased as difficult if possible.
(But this is only my humble opinion.)

If something is "difficult if not impossible", it is difficult and perhaps impossible. "Difficult if possible" doesn't work.

[suprunp]

If something is "difficult if not impossible", it is difficult and perhaps impossible. "Difficult if possible" doesn't work.

This means that difficult if possible can only be perceived as difficult, but possible.
Am I right?

Thanks.