void cparc(Arc oa, State from, State to) {
        newarc(oa.type, oa.co, from, to);
    }
void cparc(Arc oa, State from, State to) {
        newarc(oa.type, oa.co, from, to);
    }
void cparc ( Arc oa , State from , State to ) { newarc ( oa . type , oa . co , from , to ) ; }
cparc - allocate a new arc within an NFA, copying details from old one
cparc - allocate a new arc within an NFA copying details from old one