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