"Ernst Ferdinand Adolf Minding (Russian: Фердинанд Готлибович Миндинг; January 11 1806 [O.S. December 30] – May 13 [O.S. May 1] 1885) was a German-Russian mathematician known for his contributions to differential geometry. He continued the work of Carl Friedrich Gauss concerning differential geometry of surfaces, especially its intrinsic aspects. Minding considered questions of bending of surfaces and proved the invariance of geodesic curvature. He studied ruled surfaces, developable surfaces and surfaces of revolution and determined geodesics on the pseudosphere. Minding´s results on the geometry of geodesic triangles on a surface of constant curvature (1840) anticipated Beltrami´s approach to the foundations of non-Euclidean geometry (1868)." - (en.wikipedia.org 13.12.2020)
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