I. Introduction
Xiaobai wrote Latex double column, and found that the distance between letters is too close after automatic typesetting. For the sake of beauty, I hope to fine-tune it.
2. Technical realization
The operation is simple, just insert "\!" in the formula.
Three. Examples
u_0(k+1)=u_0(k)\!+\!k_P\!fal(e_1\!,\!\alpha_1\!,\!\delta_1\!)\!+\!k_D\!fal\!(\!e_2\!,\!\alpha_2\!,\!\delta _2\!)\\