The Functional Equation f g = f: 10818

Cezar Joita, Robin Chapman. The Functional Equation f g = f: 10818. The American Mathematical Monthly, 109(5):479-480, 2002. [doi]

@article{JoitaC02,
  title = {The Functional Equation f g = f: 10818},
  author = {Cezar Joita and Robin Chapman},
  year = {2002},
  url = {http://www.jstor.org/stable/2695662},
  researchr = {https://researchr.org/publication/JoitaC02},
  cites = {0},
  citedby = {0},
  journal = {The American Mathematical Monthly},
  volume = {109},
  number = {5},
  pages = {479-480},
}