/koh"shee ree"mahn, koh shee"-/ , Math.
equations relating the partial derivatives of the real and imaginary parts of an analytic function of a complex variable, as f ( z ) = u ( x,y ) + iv ( x,y ), by du / dx = dv / dy and du / dy = - dv / dx.
[ named after A. L. CAUCHY and G. F. B. RIEMANN ]