Reference for Eruvin 31:10
לימא תיהוי תיובתיה דר"ה בריה דרב יהושע אמר לך וליטעמיך אימא סיפא אם היה עומד מרובה על הפרוץ אף כנגד הפרוץ מותר הא כפרוץ אסור
over against the standing parts and forbidden over against the gaps.<span class="x" onmousemove="('comment',' Thus we have three categories: (i) It is not necessary for each gap to be less in width than a reed where the reeds are less than three handbreadths in width; and even if a gap is as wide as or wider than a reed, provided it is not wider than three handbreadths, all the fence is valid. (ii) It is necessary for each gap to be less in width than a reed where the reeds are three, or from three to four handbreadths in width. A gap of three or more handbreadths destroys the validity of the entire fence even that of its standing parts. (iii) Where the standing parts of a fence are considerable, their validity is not affected by the gaps, though it is forbidden to sow over against one side of the gaps if vines grow on the other.');"><sup>13</sup></span> If, however, the standing parts exceeded the gaps it is permitted<span class="x" onmousemove="('comment',' In any of three cases enumerated.');"><sup>14</sup></span>