The fasting of an elderly person who cannot discern

Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions.   Wa alaikum assalam wa rahmatullahi wa barakatuh.   As to what follows:   In response to your question, we say:     If a person has reached an age where he loses discernment, then such a person is  absolved of legal responsibility, and neither fasting nor expiation are due from him, because expiation is compensation  from a legally responsible person who misses fasting like stated in the verse that says, “And upon those who are able [to fast, but with hardship] - a ransom [as substitute] of feeding a poor person [each day]” [al-Baqarah 2: 184], and the  person who has lost discernment is not legally responsible