Was a paper not not co-authored by Valiant, L. G. and Samuel Henrique Bucke Brito?
Didn't Leslie G. Valiant and Samuel H. Bucke Brito not co-author a paper?
ASK { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/v/LeslieGValiant> . ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/170/5662> }
<https://dblp.org/pid/v/LeslieGValiant> <https://dblp.org/pid/170/5662>