hyphen in subscript
Sometimes, the hyphen as subscript doesn't appear : see the A_- in the fragment
sage: pp= Graphics()
sage: pp+=text("$A_-$",(0,0),axes=False,fontsize=20)
sage: pp+=text("$B_-C_+$",(1,0),axes=False,fontsize=20)
sage: pp
Some hint ?
lg