| `Us
| `Coercions
| `CoercionsFull
+ | `TeX
+ | `Grammar
]
type mathViewer_entry =
| `About `Us -> "about:us"
| `About `Coercions -> "about:coercions?tred=true"
| `About `CoercionsFull -> "about:coercions"
+ | `About `TeX -> "about:tex"
+ | `About `Grammar -> "about:grammar"
| `Check _ -> "check:"
| `Cic (_, _) -> "term:"
| `Dir uri -> uri
| "about:us" -> `About `Us
| "about:coercions?tred=true" -> `About `Coercions
| "about:coercions" -> `About `CoercionsFull
+ | "about:tex" -> `About `TeX
+ | "about:grammar" -> `About `Grammar
| _ -> (* only about entries supported ATM *)
raise (Invalid_argument "entry_of_string")