首先,列写出Birkhoff系统Lie对称性的确定方程、结构方程和守恒量;其次,给出Birkhoff系统Lie对称性逆问题的两种提法和解法.结果表明:同一Birkhoff函数(Birkhoff函数组)和第一积分可以对应不同的Birkhoff函数组(Birkhofr函数)和不同的Lie对称性,也可以对应相同的Lie对称性和不同的Birkhoff函数组(Birkho仃函数).
First, the determining equations, the structure equations and the conserved quantities of Lie symmetries for a Birkhoffian system were given; then two formulations and solutions of the inverse problems of Lie symmetries for the system were presented. The results show that the same Birkhoman(Birkhoff's functions) and first integral can corre- spond to different Birkhoff's functions(Birkhoffian) and different Lie symmetries, and can also correspond to the same Lie symmetry and different Birkhoff's functions(Birkhoffian).