It is evident that Chulin, which was slaughtered in the Azohroh, is not a Torah prohibition - אלמא חולין שנשחטו בעזרה לאו דאורייתא
Summary:
All agree that a woman cannot be מקודשת even with an איסור הנאה מדרבנן. It is possible (in the הו"א) to distinguish (by איסורי דרבנן) whether there is some תורה aspect to this איסור.
And similarly an animal which was slaughtered in the Azohroh - וכן חיה שנשחטה בעזרה
Summary:
The fact that even a חיה שנשחטה בעזרה needs to be burnt proves that חולין שנשחטו בעזרה is דאורייתא, for otherwise there would be no such גזירה.
And two verses that come as one cannot teach - ושני כתובים הבאים כאחד אין מלמדין
Summary:
It may be considered ב' כתובים הבאין כאחד even if only one cannot be derived from the other. It is also considered ב' כתובים even if the details cannot be derived as long as the main rule can be derived from the other case.
