XJ is used to connect sub-phrases that occur in various idiomatic coordinating expressions. Currently, it is used only to implement ... not only X, but Y, linking to infinitives:
+-------------------XJi-------------------+
| +----------Js---------+ |
+-----I----+ | +-------Ds------+ |
+--Sp--+ +IDBM+--I-+-MVp-+ | +---AN---+ +-Xd-+----I---+--Ox-+
| | | | | | | | | | | | |
you should.v not only ask.v for.p your money.n-u back.n , but.j-r demand.v it
Other possible uses of this link (not currently implemented) might cover other idiomatic coordinating expressions, such as:
Note also that the VJb link is used to form not only ... but also... expressions with past-tense verbs:
+----------Sp---------+
| +IDBM+--Db-+-VJb*i-+--VJr*i-+
| | | | | |
we not only ate.v-d but.j-b drank.v-d
This usage should probably be harmonized with the XJ constructions,
into a more cherent approach to the overall problem.
See also the conjunction overview.
Grammar Documentation Page.