12．（2023•重庆模拟）已知向量a→,b→\overrightarrow{a},\overrightarrow{b}a,b的夹角为60∘60\circ60∘，∣a→∣=2∣b→∣=2\vert {\overrightarrow{a}}\vert =2\vert {\overrightarrow{b}}\vert =2∣a∣=2∣b∣=2，若对任意的x1x_{1}x1、x2∈(m,+∞)x_{2}\in (m,+\infty )x2∈(m,+∞)，且x1<x2x_{1}<x_{2}x1<x2，x11nx2−x21nx1x1−x2>∣a→−2b→∣\frac{{x_1}1n{x_2}-{x_2}1n{x_1}}{{x_1}-{x_2}}>\vert {\overrightarrow{a}-2\overrightarrow{b}}\vertx1−x2x11nx2−x21nx1>∣a−2b∣，则mmm的取值范围是((( )))