Properties of algebraic K-functors

Abstract

Let

$$\begin{array}{*{20}{c}} {R\mathop \to \limits^{{i_1}} {R_1}}\\ {^{{i_2}} \downarrow \quad { \downarrow ^{{j_1}}}}\\ {R2\mathop \to \limits^{{i_2}} {R^1}} \end{array}$$

((1))

be a cartesian square of rings with unit and with at least one of the homomorphisms j₁ or j₂ surjective.