Reference for Shabbat 57:5
והא דרב לאו בפירוש איתמר אלא מכללא איתמר דרב אכל תמרי ושדא קשייתא לבוכיא אמר ליה רבי חייא בר פחתי כנגדו ביו"ט אסור קיבלה מיניה או לא קיבלה מיניה
that is R. Judah's opinion; but R. Simeon permits it. One may heat with nuts: if they are eaten, one must not heat with their shells: this is R. Judah's ruling; but R. Simeon permits it. Now, they are [all] necessary. For if we were told the first, R. Judah rules [thus] in that case, because it was a utensil before but only a fragment of a utensil now, and so it is nolad, hence forbidden; but as for dates, since they were stones originally and are stones now, I might argue that it is well [permitted]. And if we were informed [this] of dates, I might say, [the reason is] because they [the stones] were originally concealed but are now revealed; but as for nutshells, which were uncovered originally and are uncovered still, I might argue that it is well [permitted]. Thus they are necessary.<span class="x" onmousemove="('comment',' Reversing the argument, all cases are necessary for R. Simeon's view. ');"><sup>8</sup></span>