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print "${X()} ${X()}\n";
print "${X()}${X()}\n";
$ perl -E'my $x=5; sub X { \(++$x) } say ${ X() } + ${ X() };' 14 $ perl -E'my $x=5; sub X { \(++$x) } say ${ X() } + 0 + ${ X() };' 13