Editing Unary numeral system (section)

==Operations==
[[Addition]] and [[subtraction]] are particularly simple in the unary system, as they involve little more than [[string concatenation]].<ref>{{citation
 | last = Sazonov
 | first = Vladimir Yu.
 | contribution = On feasible numbers
 | doi = 10.1007/3-540-60178-3_78
 | mr = 1449655
 | pages = [https://archive.org/details/logiccomputation0000unse/page/30 30–51]
 | publisher = Springer, Berlin
 | series = Lecture Notes in Comput. Sci.
 | title = Logic and computational complexity (Indianapolis, IN, 1994)
 | volume = 960
 | year = 1995
 | isbn = 978-3-540-60178-4
 | url = https://archive.org/details/logiccomputation0000unse/page/30
 }}. See in particular p. 48.</ref> The [[Hamming weight]] or population count operation that counts the number of nonzero bits in a sequence of binary values may also be interpreted as a conversion from unary to [[binary number]]s.<ref name="blaxell">{{citation
 | last = Blaxell | first = David
 | editor1-last = Hogben | editor1-first = David
 | editor2-last = Fife | editor2-first = Dennis W.
 | contribution = Record linkage by bit pattern matching
 | pages = 146–156
 | publisher = U.S. Department of Commerce / National Bureau of Standards
 | series = NBS Special Publication
 | title = Computer Science and Statistics--Tenth Annual Symposium on the Interface
 | url = https://books.google.com/books?id=-MrJPUqTPh8C&pg=PA146
 | volume = 503
 | year = 1978}}.</ref> However, [[multiplication]] is more cumbersome and has often been used as a test case for the design of [[Turing machine]]s.<ref>{{citation|at=[https://archive.org/details/introductiontoau00hopc/page/ Example 7.7, pp. 158–159]|title=Introduction to Automata Theory, Languages, and Computation|first1=John E.|last1=Hopcroft|author1-link=John Hopcroft|first2=Jeffrey D.|last2=Ullman|author2-link=Jeffrey Ullman|publisher=Addison Wesley|year=1979|isbn=978-0-201-02988-8|url-access=registration|url=https://archive.org/details/introductiontoau00hopc/page/}}.</ref><ref>{{citation|title=The New Turing Omnibus: Sixty-Six Excursions in Computer Science|first=A. K.|last=Dewdney|author-link=A. K. Dewdney|publisher=Computer Science Press|year=1989|page=209|url=https://books.google.com/books?id=NDiU62j7jeMC&pg=PA209|isbn=9780805071665}}.</ref><ref>{{citation|title=Turing Machine Universality of the Game of Life|volume=18|series=Emergence, Complexity and Computation|first=Paul|last=Rendell|publisher=Springer|year=2015|isbn=9783319198422|url=https://books.google.com/books?id=px8_CgAAQBAJ&pg=PA83|pages=83–86|contribution=5.3 Larger Example TM: Unary Multiplication}}.</ref>