let contents = match b with
| E.Abst w -> tag "GDec" attrs ~contents:(pp_term w)
| E.Abbr v -> tag "GDef" attrs ~contents:(pp_term v)
let contents = match b with
| E.Abst w -> tag "GDec" attrs ~contents:(pp_term w)
| E.Abbr v -> tag "GDef" attrs ~contents:(pp_term v)