This paper introduces Hypersequent GV (HGV), a modular and extensible core calculus for functional programming with session types that enjoys deadlock freedom, confluence, strong normalisation. HGV exploits hyper-environments, which are collections of type environments, to ensure structural congruence is preserving. As consequence we obtain an operational correspondence between HCP -- process b...

let $pi_e(g)$ be the set of element orders of a finite group $g$‎. ‎let $nse(g)={m_nmid ninpi_e(g)}$‎, ‎where $m_n$ be the number of elements of order $n$ in $g$‎. ‎in this paper‎, ‎we prove that if $nse(g)=nse(l_2(81))$‎, ‎then $gcong l_2(81)$‎.