Any pseudo-Boolean function can be written uniquely as a [[multi-linear]] polynomial:<ref>{{Citecite journal |titlelast1=Hammer |first1=P.L. |last2=Rosenberg |first2=I. |last3=Rudeanu |first3=S.|date=1963 |title=On the determination of the minima of pseudo-Boolean functions|last1= Hammer|first1 language=ro P.L.|date = 1963|journal=Studii și cercetări matematice|last2= Rosenberg|first2 = I.|last3 = Rudeanu|first3 = S.|issue=14 14|pages=359–364|language= ro|issn=0039-4068}}</ref><ref>{{Citecite book |titlelast1=Hammer |first1=Peter L. |last2=Rudeanu |first2=Sergiu |year=1968 |title=Boolean Methods in Operations Research and Related Areas|last1= Hammer|first1 = Peter L.|publisher=Springer|year= 1968|isbn=978-3-642-85825-3|last2 = Rudeanu|first2 = Sergiu}}</ref>