### On elementary abelian 2-Sylow K₂ of rings of integers of certain quadratic number fields

A large number of papers have contributed to determining the structure of the tame kernel $K{\u2082}_{F}$ of algebraic number fields F. Recently, for quadratic number fields F whose discriminants have at most three odd prime divisors, 4-rank formulas for $K{\u2082}_{F}$ have been made very explicit by Qin Hourong in terms of the indefinite quadratic form x² - 2y² (see [7], [8]). We have made a successful effort, for quadratic number fields F = ℚ (√(±p₁p₂)), to characterize in terms of positive definite binary quadratic forms,...