Here is a small tool to help calculate the process of integrate.(It did can't work out all the integrate, but can help a bit.)
Require : Mathematica and Rubi
First, run this to install Rubi
PacletInstall["https://github.com/RuleBasedIntegration/Rubi/releases/download/4.16.1.0/Rubi-4.16.1.0.paclet"]
Second, run this to define a funcion.
<<Rubi`
IntWithStepsOfTeXForm[expr_, var_]:=With[{TeX2Str = Convert`TeX`ExpressionToTeX},
Steps[Int[expr, var], RubiPrintInformation -> False] //
Flatten //
Most //
Cases[RubiIntermediateResult[x_] :> "=&" <> (TeX2Str[HoldForm @@ x]) <>"\\\\"] //
{"\\begin{aligned}", TeX2Str@HoldForm@Int[expr, var], ##&@@#, "\\end{aligned}"} & //
StringReplace[{"\\, d"->"\\, \\mathrm{d}", "\\int" -> "\\displaystyle \\int"}] //
StringRiffle]
Third: enjoy it :P
for example: if we want calculate $\int \sqrt{1+\sqrt{x}}\,dx$
IntWithStepsOfTeXForm[Sqrt[1 + Sqrt[x]], x] // Print
and we get:
\begin{aligned} \displaystyle \int \sqrt{1+\sqrt{x}} \, \mathrm{d}x =&2 \text{Subst}\left(\displaystyle \int x \sqrt{1+x} \, \mathrm{d}x,x,\sqrt{x}\right)\\ =&2 \text{Subst}\left(\displaystyle \int \left(-\sqrt{1+x}+(1+x)^{3/2}\right) \, \mathrm{d}x,x,\sqrt{x}\right)\\ =&-\frac{4}{3} \left(1+\sqrt{x}\right)^{3/2}+\frac{4}{5} \left(1+\sqrt{x}\right)^{5/2}\\ \end{aligned}
Which can be directly copied out and used.
$$
\begin{aligned} \displaystyle \int \sqrt{1+\sqrt{x}} \, \mathrm{d}x =&2 \text{Subst}\left(\displaystyle \int x \sqrt{1+x} \, \mathrm{d}x,x,\sqrt{x}\right)\\ =&2 \text{Subst}\left(\displaystyle \int \left(-\sqrt{1+x}+(1+x)^{3/2}\right) \, \mathrm{d}x,x,\sqrt{x}\right)\\ =&-\frac{4}{3} \left(1+\sqrt{x}\right)^{3/2}+\frac{4}{5} \left(1+\sqrt{x}\right)^{5/2}\\ \end{aligned}
$$
It's speed is very fast. And easy to use.