Linear queries in statistical databases (1979)

by M D Schwartz, D E Denning, P J Denning
Venue:x2 = (1 + x2)− 2 > 0; d2 dx2 x√ 1 + x2 = −3x(1 + x2)− 52 ≤ 0. B Proof of Prop. 35 We