Exodus 35:34-35:
וּלְהוֹרֹ֖ת נָתַ֣ן בְּלִבּ֑וֹ ה֕וּא וְאָֽהֳלִיאָ֥ב בֶּן־אֲחִיסָמָ֖ךְ לְמַטֵּה־דָֽן׃ מִלֵּ֨א אֹתָ֜ם חָכְמַת־לֵ֗ב לַעֲשׂוֹת֮ כָּל־מְלֶ֣אכֶת חָרָ֣שׁ ׀ וְחֹשֵׁב֒ וְרֹקֵ֞ם בַּתְּכֵ֣לֶת וּבָֽאַרְגָּמָ֗ן בְּתוֹלַ֧עַת הַשָּׁנִ֛י וּבַשֵּׁ֖שׁ וְאֹרֵ֑ג עֹשֵׂי֙ כָּל־מְלָאכָ֔ה וְחֹשְׁבֵ֖י מַחֲשָׁבֹֽת׃
And He hath put in his heart that he may teach, both he, and Oholiab, the son of Ahisamach, of the tribe of Dan. Them hath He filled with wisdom of heart, to work all manner of workmanship, of the craftsman, and of the skilful workman, and of the weaver in colours, in blue, and in purple, in scarlet, and in fine linen, and of the weaver, even of them that do any workmanship, and of those that devise skilful works.
It seems that Oholi'av was an equal to Betzal'el. Yet we see that the Torah mentions a few items that Betzalel did on his own most notably, the Aron.
וַיַּ֧עַשׂ בְּצַלְאֵ֛ל אֶת־הָאָרֹ֖ן
And Bezalel made the ark
This is the only place where Betzalel's name is explicitly mentioned regarding making something. Was Ahili'av involved in the Aaron making as well? Do we know which items involved Ahali'av's cooperation?