Eruvin6: 8
חָמֵשׁ חֲצֵרוֹת פְּתוּחוֹת זוֹ לָזוֹ וּפְתוּחוֹת לְמָבוֹי — עֵרְבוּ בַחֲצֵרוֹת וְלֹא נִשְׁתַּתְּפוּ בַמָּבוֹי, מֻתָּרִין בַּחֲצֵרוֹת וַאֲסוּרִין בַּמָּבוֹי; וְאִם נִשְׁתַּתְּפוּ בַמָּבוֹי, מֻתָּרִין כָּאן וְכָאן. עֵרְבוּ בַחֲצֵרוֹת וְנִשְׁתַּתְּפוּ בַמָּבוֹי, וְשָׁכַח אֶחָד מִבְּנֵי חָצֵר וְלֹא עֵרַב, מֻתָּרִין כָּאן וְכָאן; מִבְּנֵי מָבוֹי וְלֹא נִשְׁתַּתֵּף, מֻתָּרִין בַּחֲצֵרוֹת, וַאֲסוּרִין בַּמָּבוֹי; שֶׁהַמָּבוֹי לַחֲצֵרוֹת כֶּחָצֵר לַבָּתִּים.
Five courtyards which open one into the other and into an alley — if they made an eruv in the courtyards but did not make a shituf in the alley, they are permitted in the courtyards but prohibited in the alley; if they did make a shituf in the alley, they are permitted here and there. If they made an eruv for the courtyards and a shituf for the alley, but one of the residents of the courtyard forgot to contribute to the eruv, they are permitted here and there; if one of the residents of the alley did not participate in the shituf, they are permitted in the courtyards, but are prohibited in the alley; for an alley is to the courtyards as a courtyard is to the houses.