Table: presidents_lifespans
Columns: president
date_of_birth
date_of_inauguration
age_at_inauguration
end_of_term
length_of_retirement
date_of_death
lifespan

Question: What was the date of the inauguration in the row with an entry of lifespan in the lifespan column?
SQL: SELECT "date_of_inauguration" FROM presidents_lifespans WHERE "lifespan" = 'lifespan'

Question: What was the date of death entry in the row that has a date of inauguration entry of date of inauguration?
SQL: SELECT "date_of_death" FROM presidents_lifespans WHERE "date_of_inauguration" = 'date of inauguration'

Question: What is the length of retirement for president Sharma, Shankar Shankar Dayal Sharma?
SQL: SELECT "length_of_retirement" FROM presidents_lifespans WHERE "president" = 'sharma, shankar shankar dayal sharma'