Carlos Knauer schrieb:
Hi. LyX wites $\\mathbb {R}^{3}$ like $\mathbb{R^3}$.
No, it converts $\mathbb {R}^{3}$ to $\mathbb{R^{3}}$which is correct. The brace around the R is not necessary and the brace around R^{3} specifies that \mathbb is only used for these characters and not for the whole formula as you defined it. Both expressions are correct and produce the same output, so what's the mistake you've seen?
regards Uwe