My question: How can we find the non$-$ fuzzy alpha cut relationship for $\backslash$alpha $=0\mathrm{.}8?$

Given is a fuzzy relation R: X $\backslash$times Y $->[0,1]$:

R $=$

y$1$ y$2$ y$3$ y$4$

x$10\mathrm{.}70\mathrm{.}30\mathrm{.}10\mathrm{.}5$

x$20\mathrm{.}40\mathrm{.}80\mathrm{.}21\mathrm{.}0$

x$30\mathrm{.}10\mathrm{.}20\mathrm{.}90\mathrm{.}9$

and a fuzzy set A $=\{0\mathrm{.}1/$x$1,1\mathrm{.}0/$x$2,0\mathrm{.}4/$x$3\}.$ Compute fuzzy set B $=$ A $$ R$,$ where

$$ is the max$-$min composition operator.