
Returns an external format spec constructed by adding information not supplied in ef-spec1 from ef-spec2 . The arguments are either symbols or lists.
If ef-spec1 is :default , return ef-spec2 .
If ef-spec1 is a list beginning with :default and ef-spec2 is a symbol, return ( ef-spec2 . (cdr ef-spec1 ))
If ef-spec1 is a list beginning with :default and ef-spec2 is a list, return ((car ef-spec2 ) . parameters ) where parameters is a destructuring lambda list containing the parameter descriptions of ef-spec1 and any additional parameter descriptions from ef-spec2 .
If ef-spec1 is a symbol other than :default , or a list beginning with a symbol other than :default , and ef-spec2 is a symbol, return ef-spec1 .
If ef-spec1 is a symbol other than :default , and ef-spec2 is a list, return ( ef-spec1 . (cdr ef-spec2 )) .
If ef-spec1 is a list beginning with a symbol other than :default , and ef-spec2 is a list, return ((car ef-spec1 ) . parameters ) where parameters is a destructuring lambda list containing the parameter descriptions of ef-spec1 and any additional parameter descriptions from ef-spec2 .