R-interface(A; B)
== l:IdLnk, tg:Id.
== subtype_rel(fpf-cap(R-da(A; source(l)); Kind-deq; rcv(l,tg); void);
== subtype_rel(fpf-cap(R-da(B; destination(l)); Kind-deq; rcv(l,tg); top)) 

latex

Definitions	IdLnk, x:A. B(x), Id, source(l), void, fpf-cap(f; eq; x; z), R-da(R; i), destination(l), Kind-deq, rcv(l,tg), top
FDL editor aliases	R-interface