This is LaTeX code:

[latex]
 
ho(x^2-2x+3+x^2+1)=ho(2x^2-2x+4)=2(2x^2-2x+4)+1=4x^2-4x+9=2(x^2-2x+3)+2(x^2+1)+1=...=(hof)+(hog)
 
[/latex]