Abstract:We shall prove that Sacks algebra is nowhere $(\frak b, \frak c, \frak c)$-distributive, which implies that Sacks forcing collapses $\frak c$ to $\frak b$.
Keywords: perfect tree, distributivity of Boolean algebra, almost disjoint refinement
AMS Subject Classification: Primary 03C25; Secondary 03E25, 06A07, 06E05