Warning: this is an htmlized version!
The original is across this link,
and the conversion rules are here.
Lua 5.1.5  Copyright (C) 1994-2012 Lua.org, PUC-Rio
> dofile "underbrace.lua"
> output = function (str) print("<<"..str..">>") end
> ubs0 [[ P 10 u   Q 01 u   \& bin 00 u    () \neg pre 32 u   Foo def   output ]]
<<\def\Foo{\underbrace{
\neg (\underbrace{
\underbrace{
P
}_{10} \&
 \underbrace{
Q
}_{01}
}_{00})
}_{32}}>>
> 
>