type box = TermBox of dim * char list
| NonTermBox of dim * char list
| ParamBox of dim * char list
| OptBox of dim * box
| RepBox of dim * box
| TermRepBox of dim * box * box
| OptRepBox of dim * box
| OrBoxList of dim * box list
| ConBox of dim * box * box
and dim = {l : float; h : float; lc : float; rc : float}
val dim_l : box -> float
val dim_h : box -> float
val dim_lc : box -> float
val dim_rc : box -> float
