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Scientific Seminar:
Topological Algebra

Speaker: 
Anatolii Savchuk & Oleg Gutik

Talk: 
The semigroup of partial cofinite isometries of positive integers, II 
When & where:  March 21, 2018, at 15^{05 } at Room 149^{a } 
Abstract: 
The semigroup $\mathbf{I}\mathbb{N}_{\infty}$ of all partial cofinite isometries of positive integers is discussed. We proved that a congruence on the semigroup $\mathbf{I}\mathbb{N}_{\infty}$ is group if and only if its restriction onto an isomorphic copy of the bicyclic semigroup in $\mathbf{I}\mathbb{N}_{\infty}$ is a group congruence. 