Is the intuitionistic bar-induction a constructive principle?

Klaus Mainzer. Is the intuitionistic bar-induction a constructive principle?. Notre Dame Journal of Formal Logic, 18(4):583-588, 1977. [doi]

@article{Mainzer77,
  title = {Is the intuitionistic bar-induction a constructive principle?},
  author = {Klaus Mainzer},
  year = {1977},
  doi = {10.1305/ndjfl/1093888122},
  url = {http://dx.doi.org/10.1305/ndjfl/1093888122},
  researchr = {https://researchr.org/publication/Mainzer77},
  cites = {0},
  citedby = {0},
  journal = {Notre Dame Journal of Formal Logic},
  volume = {18},
  number = {4},
  pages = {583-588},
}