We can (%i1) texput(me,"\\mu_e"); (%o1) \mu_e (%i2) tex(me); $$\mu_e$$ (%o2) false "$$\mu_e$$" is the right answer. But why not? (See the following) (%i3) tex("\\mu_e"); $$\mu\_e$$ (%o3) false Notice the difference of $$\mu\_e$$ and $$\mu_e$$. YC