this is _LJUST_o                    => this is JUST
a _lsimple _RteST_o th_oat          => a simple TSet that
HAS A _LPDF missing                 =>                   PDF missing A SAH
AnD hOw_L AbOuT, 123,987 tHiS_o     =>         w AbOuT, 123,987 tHiSOh DnA
a GOOD - _L_oTEST.                  => a TSET - DOOG.
here_L is_o_o_o _R a good one_o     => here is eno doog a 
And _r 123,987_LTHE_R next_o oNE:   =>           987THEtxen  oNE:,123  ndA
_R_r and the last _LONE_o IS        => SI and the last ONE  
THE _rbest _lONE and                =>                    best ENO and EHT
A REAL BIG_l_o BUG!                 =>                     !GUB GIB LAER A
a _L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_L_Rbug => a gub
AN ARABIC _l_o 123-456 NICE ONE!    =>        !ENO ECIN 456-123  CIBARA NA
AN ARABIC _l _o 123-456 PAIR        =>            RIAP   123-456 CIBARA NA
this bug 67_r_o89 catched!          => this bug 6789 catched!