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Hyper-relation is a relation between [[relation]]s, or between relations and nodes.

== Basic Symbols ==
{{:Basic Symbols}}

== Basic Concepts ==
{{:Grammar units}}

== Notation ==
Hyper-relations and relations are represented in the same way, i.e.,
 rel:scope(arg1;arg2;...;argn)
where:
*rel is the name of the hyper-relation
*scope is the [[scope]] of the hyper-relation
*arg1, arg2, ... are the arguments of the hyper-relation
The only difference between relations and hyper-relations is that the latter has at least one relation as one of its arguments, e.g.:
*rel(rel1(arg1;arg2);arg3;...;argn)
As in case of [[relation]]s, the main [[scope]] is 00 and it is not shown, by default:
*''rel(rel1:01(arg1;arg2);arg3;...;argn) '' is the same as ''rel:00(rel1:01(arg1;arg2);arg3;...;argn)''  (i.e., the relation ''rel'' belongs to the main scope, i.e., the main graph)

== Examples ==
Examples of hyper-relations
*XP(XB(%a;%b);%c) - a syntactic relation XP between the syntactic relation XB(%a;%b) and the node %c
*and(agt([a];[b]);agt([a];[c])) - a semantic relation "and" between the semantic relations agt([a];[b]) AND agt([a];[c])
== Properties of hyper-relations ==
;A hyper-relation may have one single relation as each argument
*XP(XB(%a;%b);%c) - the source argument of the hyper-relation XP is a relation
*XP(%a;XB(%b;%c)) - the target argument of the hyper-relation XP is a relation
*XP(VC(%a;%b);VA(%a;%c)) - the source and the target argument of the hyper-relation XP are relations
*<strike>XP(VC(%a;%b)VA(%a;%c);VS(%a;%d))</strike> - a hyper-relation may not have more than one relation as one single argument (in this case, the hyper-relation XP contained two relations as the source argument)
;Differently from [[nodes]], relations do not have elements (strings, headwords, features and indexes)
*<strike>XP(XB(%a;%b),"ab",[ab],<nowiki>[[ab]]</nowiki>,A,B;%c)</strike> (the relation XB(%a;%b) may not have strings, UWs, headwords or any features)