Reference for Eruvin 32:23
היכא איתמר דרב נחמן ואיתימא רב ביבי בר אביי אהא דתנן כל מחיצה שאינה של שתי וערב אינה מחיצה דברי ר' יוסי בר' יהודה
or would you infer from this that where the standing parts [of a partition or barrier] exceed a gap in it [only by combining those] on its two sides they are nevertheless valid?<span class="x" onmousemove="('comment',' Lit., 'is a standing', but this is contrary to the law.');"><sup>50</sup></span> But<span class="x" onmousemove="('comment',' The question in the present form being untenable.');"><sup>51</sup></span> it is this that R'Hamnuna asked: [What is the ruling where one] brought for instance a mat that measured seven handbreadths and a fraction, and cut out in it [a hole of] three handbreadths leaving [untouched the remaining] four handbreadths<span class="x" onmousemove="('comment',' On one side of the gap.');"><sup>52</sup></span>