Square exponent of irrationality of ln 2 / A. A. Polyanskii. //Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2012. № 1. P. 25-30 [Moscow Univ. Math. Bulletin. Vol. 67, N 1, 2012.].
A new proof of the theorem on the non-quadraticity measure ln 2 is given in the paper.
Key words: non-quadraticity measure ln 2.