Authors: Joseph KRASIL'SHCHIK, Michal MARVAN

Using covering theory approach (zero-curvature representations with the gauge group SL₂), we insert the spectral parameter into the Gauss--Mainardi--Codazzi equations in Tchebycheff and geodesic coordinates. For each choice, four integrable systems are obtained.

15 pages, LaTeX-2e (AmSLaTeX 1.2).

To compile source files (.tex) one needs the title page style files titlatex.tex.