# config-root.rnc
namespace rng = "http://relaxng.org/ns/structure/1.0"
namespace dc   = "http://purl.org/dc/terms"
namespace dml  = "http://example.org/ns/dml"
namespace compat ="http://relaxng.org/ns/compatibility/annotations/1.0"
namespace cfg  = "http://example.org/ns/cfg"

start = element-config
element-config = element cfg:config { config-contents }

config-contents = empty

config-contents &= external "interfaces.rnc" ?
config-contents &= external "dhcp.rnc" ?