A "normal" function call, exporting to PDF, but not ODT

"Pseudo-function returning a LaTeX pseudo-result."
"\\[\\displaystyle{\\sin\\left(\\frac{a}{b}\\right)}\\]"

This contraption allows to export to ODT :

(princ R1)

\[\displaystyle{\sin\left(\frac{a}{b}\right)}\]

A more intricate example. This exports to PDF, but not to ODT :

a, b = var("a, b")
R = str(LatexExpr("\\[\\displaystyle{%s}\\]"%latex(tan(a+b) == tan(a+b).trig_expand())))
R += "\n\n"
R += str(LatexExpr("\\[\\displaystyle{%s}\\]"%latex(tan(a-b) == tan(a-b).trig_expand())))
LatexExpr(R)

Again, we have to export it raw to export to ODT :

print(R2)

\[\displaystyle{\tan\left(a + b\right) = -\frac{\tan\left(a\right) + \tan\left(b\right)}{\tan\left(a\right) \tan\left(b\right) - 1}}\]

\[\displaystyle{\tan\left(a - b\right) = \frac{\tan\left(a\right) - \tan\left(b\right)}{\tan\left(a\right) \tan\left(b\right) + 1}}\]