The rule
S -> aSAbb | aA
does not remain recursive. The left recursive rule has the form
A -> Au
where u is the sequence of terminals and non-terminals. To remove the character Son the right side of the rules S, consider:
S => aSAbb
=> a(aSAbb)Abb
=> a^n(aA)(Abb)^n
S . :
S -> aKAbb | aA
K -> aSAbb | aA
,
S => aSAbb
=> a(aSAbb)Abb
=> a(a(aSAbb)Abb)Abb
S => aKAbb
=> a(aSAbb)Abb
=> a(a(aKAbb)Abb)Abb
aA ( : , , ).