This operator is not standard, but an approximate posit multiplier with a bounded relative error of 11.11%.
It was proposed in the following paper, please refer to it for more details:
R. Murillo, A. A. Del Barrio Garcia, G. Botella, M. S. Kim, H. Kim and N. Bagherzadeh, "PLAM: a Posit Logarithm-Approximate Multiplier," in IEEE Transactions on Emerging Topics in Computing, doi: 10.1109/TETC.2021.3109127.