"Right working" also overlaps with both Indo-European "*ár-" "to (properly) join together" and with the notion of existence and realization (to make real). The word for "established", "ar"ə"ta-", also means "proper". The antonymic "anar"ə"ta-" (or "anar"ə"θa-") means "improper" In Zoroastrian tradition, prayers must be enunciated with care for them to be effective. The Indo-Iranian formula "*sātyas mantras" ("Yasna" 31.6: "haiθīm mathrem") "does not simply mean 'true Word' but formulated thought which is in conformity with the reality' or 'poetic (religious) formula with inherent fulfillment (realization)'".