What are the essential components that invalidate prayer if omitted?

Primary text

Prayer is nullified by omitting specific obligatory components, whether done intentionally or forgetfully. This absolute requirement applies to ten specific actions: the opening takbir (takbirat al-Ihram), recitation of Al-Fatiha for the Imam and one praying alone, standing (Qiyam), bowing until tranquil (tuma'ninah in rukūʿ), rising until straight (tuma'ninah in i'tidal), prostrating until tranquil (tuma'ninah in sujūd), sitting between the prostrations until tranquil (tuma'ninah in julus), the final testimony (tashahhud), sitting for the final testimony, the final salutation (salam), and maintaining the proper sequence of these acts. The evidence for the obligation of these elements is derived from the hadith of the man who prayed poorly, where the Prophet, peace be upon him, commanded him to repeat the prayer and then instructed him on these specific movements, indicating that one is not considered praying without them. Furthermore, this implies they are not waived by forgetfulness, as the ignorant person is treated like the forgetful one in this context.