let mk_baseuri root extra =
let chop name =
+(* FG: there is no reason why matita should edit just matita files
+ matita's editor is good on its own and has interesting facilities
+ including predefined virtuals
assert(Filename.check_suffix name ".ma" ||
Filename.check_suffix name ".mma");
+*)
try Filename.chop_extension name
with Invalid_argument "Filename.chop_extension" -> name
in