无界区间 meaning in English

unbounded interval

Equation ( 4 ) is said to belong to limit circle type if all solutions of equation ( 4 ) belong to l ~ ( 2 ) ( simply denoted by l . c . ) equation ( 4 ) is said to belong to lagrange stable if all solutions of equation ( 4 ) belong to ( simply denoted by l . s . ) . in chapter 4 , we study criteria for the linear nonhomogeneous differential equation belonging to the limit circle type
方程( ’ )称为极限圆型的，若方程( ’ )的所有解都属于护[ a ， co ) (简记为l . c . ) ;方程( ’ )称为拉格拉日稳定，若方程( ’ )的所有解均属于lco [ a ， co ) (简记为l . s . ) .由于方程( ’ )解的平方可积性及有界性的研究在微分算子理论、按微分方程的特征函数展开理论以及无界区间上受控系统的最佳控制理论等方面具有重要应用