Nedarim 81b - Tashmish: Is it an Inuy?

The gemara on 80b implies that if something is considered an inuy in the context of nedarim, it should also be an inuy in the context of yom kippur and be chayev kareis. The only distinction is, that by nedarim even refraining from activities that will lead to a delayed inuy qualify as inuy (such as not bathing), whereas by yom kippur we only consider it inuy if the effect of the inuy is immediate. There is another distinction based on the Ran 80b, that kareis is only applicable if it is an inuy that leads to "ibud nefesh", such as refraining from eating, so rechitzah may be assur m'doraysa both by neder and y.k. even though there isn't kareis. The bottom line is that anything that the Inuy of Neder and Y.K. (so long as the effect is immediate) are dependent on one another, if it is inuy d'oraysa by neder then it is d'oraysa by Y.K. (just that there isn't kareis since there isn't ibud nefesh by anything except eating and drinking), and if it is not recognized as inuy d'oraysa by neder then it is not d'oraysa by Y.K. and visa versa.

Based on this, Tashmish HaMitah, if it is considered an inuy by Y.K. it should be inuy by neder (to allow hafara), and if it is not considered inuy by Y.K. it should not be inuy by neder. Whether the inuyim are assur m'doraysa by Y.K. is a big machlokes Rishonim (Ran and Tosafos in the last perek of Yoma). Therefore, R' Yossi (who is the author of the braisa 81b) who considers tashmish to be devarim shebeino l'veina and not inuy, should consider it only d'rabonon by Y.K. Seemingly, when the gemara questions according to the Rabonon whether tashmish is considered inuy nefesh or devarim sh'beino l'veina by neder, is really asking also by Y.K. whether it is d'oraysa or d'rabonon, and l'maskana should be dependent on the machlokes rishonim in Yoma.

However, the Shita (81b) says that even if Tashmish is d'oraysa by Y.K. that is only for a man where abstinence is more difficult, but for a woman where abstinence is easier it would not be considered inuy. Based on this, the question of the gemara whether tashmish is inuy or devarim shbeino l'veina by nedarim, is only a question by a woman, but for a man all may agree that it is considered inuy d'oraysa (according to those who hold that the inuyim are d'oraysa, just exempt from kareis). Therefore, if we assume that by neder abstinence is not inuy d'oraysa by a woman, then by Y.K. we would also make a distinction between a man and woman. For a man tashmish would be a d'oraysa violation and for a woman only d'rabonon.