. "x existence starts and ends during y if and only if the start of x is part of y and the end of x is part of y. Formally: x existence starts and ends during y iff \u03B1(x) >= \u03B1(y) & \u03B1(x) <= \u03C9(y) & \u03C9(x) <= \u03C9(y) & \u03C9(x) >= \u03B1(y)" . "Chris Mungall" . . . "The relations here were created based on work originally by Fabian Neuhaus and David Osumi-Sutherland. The work has not yet been vetted and errors in definitions may have occurred during transcription." . "existence starts and ends during" .