Fig. 4
Value distribution of \(u_{1} ,u_{2}\) for experiment on the co-development of two well-matched languages. Sub-image a t = 100, sub-image b t = 300, sub-image c t = 500 and sub-image d: t = 700. Sub-images a–d show the changes in the frequency of the two well-matched languages at different moments. With the advance of observed time moment, the two well-matched languages show co-development in the process of competition