\[ \int \sin (b x) \text {Si}(b x) \, dx \]
Optimal antiderivative \[ -\frac {\cos \left (b x \right ) \sinIntegral \left (b x \right )}{b}+\frac {\sinIntegral \left (2 b x \right )}{2 b} \]
command
integrate(sin_integral(b*x)*sin(b*x),x, algorithm="fricas")
Fricas 1.3.8 (sbcl 2.2.11.debian) via sagemath 9.6 output
\[ -\frac {2 \, \cos \left (b x\right ) \operatorname {Si}\left (b x\right ) - \operatorname {Si}\left (2 \, b x\right )}{2 \, b} \]
Fricas 1.3.7 via sagemath 9.3 output
\[ {\rm integral}\left (\sin \left (b x\right ) \operatorname {Si}\left (b x\right ), x\right ) \]