x1 is as if it were (and it might be) in relation x2 with something.
This predicate may be used to “delete” argument slots from another predicate, for example for expressing «he asked “is there somebody?” even though he knew there is no one to hear him» using a predicate «x₁ asks to x₂ question x₃», where the the last slot is unwelcome. See also: zi'o.