Reference for Taanit 56:1
מאי שנא הלל דדחי דידיה ומאי שנא מוסף דלא דחי דידיה
Why is Hallel different that it suspends its own Ma'amad<span class="x" onmousemove="('comment',' On the day when Hallel is recited is the corresponding Ma'amad prayer of the Shaharith eliminated.');"><sup>1</sup></span> while Musaf does not supersede its own Ma'amad?<span class="x" onmousemove="('comment',' On the day when there is Musaf the Ma'amad of the Minhah is eliminated and not the one attached to the Musaf.');"><sup>2</sup></span> - R'Ashi replied: If [Musaf] suspends the Ma'amad of a service of which it is not part, [i.e., Minhah] all the more should it suspend its own Ma'amad? - R'Kashisha then said: This is what I mean to say: Let it [Musaf] suspend its own Ma'amad only!<span class="x" onmousemove="('comment',' And not also that of Minhah, having a similar effect as Hallel.');"><sup>3</sup></span>