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sub lambda {
    my $f = $_[1];
...
        }
    }
}

sub Y {
    my ( $curried_rec ) = @_;
...
        $curried_rec->( sub { $f2->( $f2 )->( @_ ) } )
    } )
}

print Y( sub {
    my ( $rec ) = @_;
...
} )->( 10 );;

3628800