Profitless delays for permanence in a pure-delayed nonautonomous Lotka-Volterra competitive system with infinite delays and discrete delays

摘要

This paper studies a pure-delayed nonautonomous Lotka-Volterra competitive system with infinite delays and discrete delays. Sufficient conditions are obtained for the permanence of the system. The permanence of the system is dependent of time delays, that is, they are "profitless" delays because they have effect on the permanence of the system.