A very absolute Pi-1-2 real singleton
David, René
HAL, hal-00416489 / Harvested from HAL
Text on HAL
I give a class forcing that adds a real which is Pi-1-2 and for which no forcing extension (by a set of conditions) can destroy this definability.
Publié le : 1982-01-01
Classification:  [MATH.MATH-LO]Mathematics [math]/Logic [math.LO] 
@article{hal-00416489,
     author = {David, Ren\'e},
     title = {A very absolute Pi-1-2 real singleton},
     journal = {HAL},
     volume = {1982},
     number = {0},
     year = {1982},
     language = {en},
     url = {http://dml.mathdoc.fr/item/hal-00416489}
}

David, René. A very absolute Pi-1-2 real singleton. HAL, Tome 1982 (1982) no. 0, . http://gdmltest.u-ga.fr/item/hal-00416489/