Fortunately when a stuck seat Post was in so solidly the Brazing holding the seat stays Broke , before the Post would budge.
a friend .. had the brazing torch to heat the steel to get the aluminum post out, then re braze the seat stay tips to the seat Lug.
The value of that seatpost has plummeted ..
Now Everyone.. Let this be a Warning to You,_ take out your seat posts, add A little Grease in your seat tubes and put the Post back in again .