Retarded differential equations (RDEs) are differential equations having retarded arguments.
https://www.sciencedirect.com/science/article/pii/S037704270...
https://en.wikipedia.org/wiki/Degenerate_energy_levels
Retarded differential equations (RDEs) are differential equations having retarded arguments.
https://www.sciencedirect.com/science/article/pii/S037704270...