Self-orthogonal codes over a non-unital ring and combinatorial matrices

Minjia Shi, Shukai Wang, Jon-Lark Kim +1

There is a local ring $E$ of order $4,$ without identity for the multiplication, defined by generators and relations as $E=\langle a,b \mid 2a=2b=0,\, a^2=a,\, b^2=b,\,ab=a,\, ba=b…