Binary operation/Table/4/2/Exercise

On the set

${}M=\{a,b,c,d\}\,,$

we consider the binary operation ${}\star$ given by the table

${}\star$	${}a$	${}b$	${}c$	${}d$
${}a$	${}b$	${}a$	${}c$	${}a$
${}b$	${}d$	${}a$	${}b$	${}b$
${}c$	${}a$	${}b$	${}c$	${}c$
${}d$	${}b$	${}d$	${}d$	${}d$

1. Compute

   $b\star (a\star (d\star a)).$

2. Does there exist a neutral element for ${}\star$?

Create a solution