00817nam0-22003011i-450-990001056020403321000105602FED01000105602(Aleph)000105602FED0100010560220000920d1963----km-y0itay50------baengDegrees of Unsolvabilityby Gerald E. SacksPrinceton [N.J.]Princeton University Press1963ix, 174 p.24 cmAnnals of mathematics studies55LogicaRicorsività160Sacks,Gerald E.50334ITUNINARICAUNIMARCBK9900010560204033217-1274745FI1FI1Degrees of Unsolvability340517UNINAING01