| Pres.Mspace _ -> fixed_rendering string_space
| Pres.Mrow (attrs, children) ->
let children' = List.map aux_mpres children in
(fun size -> render_row size false children')
| Pres.Mfrac (_, m, n) ->
| Pres.Mspace _ -> fixed_rendering string_space
| Pres.Mrow (attrs, children) ->
let children' = List.map aux_mpres children in
(fun size -> render_row size false children')
| Pres.Mfrac (_, m, n) ->