type dtd_attr_default = Types.dtd_attr_default = | DTDDefault of string | 
| DTDRequired | 
| DTDImplied | 
| DTDFixed of string | 
type dtd_attr_type = Types.dtd_attr_type = | DTDCData | 
| DTDNMToken | 
| DTDEnum of string list | 
| DTDID | 
| DTDIDRef | 
type dtd_item = Types.dtd_item = | DTDAttribute of string * string * dtd_attr_type * dtd_attr_default | 
| DTDElement of string * dtd_element_type |