Homotopy principle
THE PHENOMENON THAT, FOR CERTAIN PARTIAL DIFFERENTIAL EQUATIONS, THE SPACE OF (HOLONOMIC) SOLUTIONS IS HOMOTOPY-EQUIVALENT TO THE SPACE OF NON-HOLONOMIC SOLUTIONS, WHICH CAN BE DEALT WITH HOMOTOPY-THEORETICALLY
H-principle; Homotopy-principle
In mathematics, the homotopy principle (or h-principle) is a very general way to solve partial differential equations (PDEs), and more generally partial differential relations (PDRs). The h-principle is good for underdetermined PDEs or PDRs, such as the immersion problem, isometric immersion problem, fluid dynamics, and other areas.