160 Yevamot 12/3-4

(ג) חָלְצָה וְרָקְקָה, אֲבָל לֹא קָרְאָה, חֲלִיצָתָהּ כְּשֵׁרָה. קָרְאָה וְרָקְקָה, אֲבָל לֹא חָלְצָה, חֲלִיצָתָהּ פְּסוּלָה. חָלְצָה וְקָרְאָה, אֲבָל לֹא רָקְקָה, רַבִּי אֱלִיעֶזֶר אוֹמֵר, חֲלִיצָתָהּ פְּסוּלָה. רַבִּי עֲקִיבָא אוֹמֵר, חֲלִיצָתָהּ כְּשֵׁרָה. אָמַר רַבִּי אֱלִיעֶזֶר, כָּכָה יֵעָשֶׂה (דברים כה), כָּל דָּבָר שֶׁהוּא מַעֲשֶׂה, מְעַכֵּב. אָמַר לוֹ רַבִּי עֲקִיבָא, מִשָּׁם רְאָיָה, כָּכָה יֵעָשֶׂה לָאִישׁ, כָּל דָּבָר שֶׁהוּא מַעֲשֶׂה בָאִישׁ:

(ד) הַחֵרֵשׁ שֶׁנֶּחֱלַץ וְהַחֵרֶשֶׁת שֶׁחָלְצָה, וְהַחוֹלֶצֶת לַקָּטָן, חֲלִיצָתָהּ פְּסוּלָה. קְטַנָּה שֶׁחָלְצָה, תַּחֲלֹץ מִשֶּׁתַּגְדִּיל. וְאִם לֹא חָלְצָה, חֲלִיצָתָהּ פְּסוּלָה:

(3) [If] she performed Chalitzah and spat [before the Yavam], but did not read [the verses associated with the ceremony], her Chalitzah is valid. [If] she read [the text] and spat but did not perform Chalitzah [loosen his shoe] her Chalitzah is invalid. [If] she performed Chalitzah and read [the text] but did not spit - Rabbi Eliezer says: Her Chalitzah is invalid; [but] Rabbi Akiva says: Her Chalitzah is valid. Rabbi Eliezer said [interpreted the words], "So shall it be done" (Devarim 25:9), [implies that] all actions are critical. Rabbi Akiva said to him: [Will you bring] a proof from there? [Does the phrase not conclude with the words] "So shall it be done to the man" [which implies that only] actions done to the man [are critical, which excepts spitting].

(4) [If] a deaf-mute [Yavam] underwent Chalitzah, or if a deaf-mute [Yevamah] performed Chalitzah, or if a [Yevamah] performed Chalitzah for a minor, her Chalitzah is invalid. [If] a minor [Yevama] performed Chalitzah, she must perform Chalitzah [again] when she attains majority. And if she does not perform Chalitzah [again] her Chalitzah is invalid.