Abstract. A topological group H is called ω -narrow if for every neighbourhood V of it’s identity element there exists a countable set A such that V A = H = AV. A semigroup G is called a generalized group if for any x ∈ G there exists a unique element e(x) ∈ G such that xe(x) = e(x)x = x and for every x ∈ G there exists x − 1 ∈ G such that x − 1x = xx − 1 = e(x). Also le...

We performed a systematic mapping of validation methods used in digital soil (DSM), order to gain an overview current practices and make recommendations for future publications on DSM studies. A search screening procedure, largely following the RepOrting standards Systematic Evidence Syntheses (ROSES) protocol, was carried out. It yielded database 188 peer-reviewed studies from past two decades...