go to the DATA-LENS․TRANSDUCERS․INTERNALS∶∶UNWRAP ❨eql DATA-LENS․TRANSDUCERS∶∶LIST-BUILDER❩ COMMON-LISP∶∶T method (The data-lens/beta/transducers Reference Manual)
The node you are looking for is at go to the DATA-LENS․TRANSDUCERS․INTERNALS∶∶UNWRAP ❨eql DATA-LENS․TRANSDUCERS∶∶LIST-BUILDER❩ COMMON-LISP∶∶T method.