[If] any of the parts that convey tumah through ohel were divided and one brought [the pieces] into a house, R' Dosa ben Horkinas rules [that the person remains] tahor, but the Sages rule [that he becomes] tamei. How so? If one [simultaneously] touches two half-olive-sized [pieces] of neveilah or carries them; or, in the case of a corpse, if one touches a half-olive-sized piece while he forms a “roof” over a half-olive-sized piece, or if one touches a half-olive-sized [piece] while [another] half-olive-sized [piece] forms a “roof” over him, or he forms a “roof” over two half-olive-sized [pieces, or] he forms a “roof” over [one] half-olive-sized [piece] while [another] half-olive-sized [piece] forms a “roof” over him; [in each of these cases,] R' Dosa ben Horkinas rules [that the person remains] tahor, while the Sages rule [that he becomes] tamei. But if one touches a half-olive-sized [piece of a corpse] while something forms a roof over him and over [another] half-olive-sized [piece], or if one forms a roof over a half-olive-sized piece while something forms a roof over him and over another half-olive-sized piece, [he remains] tahor. R' Meir said: Even in this case, R' Dosa rules [that the person remains] tahor and the Sages rule [that he becomes] tamei. [In] every case [where a person is subject to tumah from two undersized pieces of a corpse, the Sages maintain that he be-comes] tamei, except [for a combination of] touch and carrying, or carrying and “roof.” This is the rule [according to the Sages:] Any [two associations] from the same category [render the person] tamei, whereas from two [different] categories [leave him] tahor.