This $is$ a maple code

HOW can I calculte $y[i],$ the code does not work

a :$=0$; h :$=$ proc $($x$)$ options operator, arrow; $0$ end proc; g :$=$ proc $($x$)$ options operator, arrow; $1$ end proc; N :$=5$; Integral$\_$ope :$=$ proc $($f$,$ psi, a$,$ x$)$ options operator, arrow; $($int$(($diff$($psi$($t$),$ t$))*($psi$($x$)-$psi$($t$))^($alpha$-1)*$f$($t$),$ t $=$ a $..$ x$,$ continuous$))/$GAMMA$($alpha$)$ end proc; A :$=$ proc $($n$,$ x$)$ local expr; if n $=0$ then expr :$=$ add$($k$^$i$*$y$[$i$]($x$),$ i $=0..$ N$)^2$; subs$($k $=0,$ expr$)$ else expr :$=$ add$($k$^$i$*$y$[$i$]($x$),$ i $=0..$ N$)^2$; $($diff$($expr$,`$$$`($x$,$ n$)))*$subs$*$k$/$factorial$($n$)=0$ end if end proc; y$[0]$ :$=$ h$($x$)+$Integral$\_$ope$($g$,$ psi, a$,$ x$)$; y$[0]$ :$=$ unapply$($y$[0],$ x$)$; for i to $5$ do y$[$i$]$ :$=($int$(($diff$($psi$($t$),$ t$))*($psi$($x$)-$psi$($t$))^($alpha$-1)*$A$($i$-1,$ t$),$ t $=0..$ x$))/$Gamma$($alpha$)$ end do