A co-projection of computable measures matched with an order relation is not always computable / M. A. Raskin. // Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2012. № 2. P. 17-20 [Moscow Univ. Math. Bulletin. Vol. 72, N 2, 2017. P. 0].
An example of two computable probabilistic measures is given on infinite binary sequences such that the two measures are comparable (there exists their coupling that forbids the pairs of symbols with the first member less than the second one), but all such couplings are incomputable.
Key words: computable probabilistic measures, measure coupling.