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<?php $i = 0; $o = (function () use(&$o, $i) { $i++; echo 'o'; if ($i < 10) { $o(); } return $o; })();
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
o Fatal error: Uncaught Error: Value of type null is not callable in /in/gRMRp:8 Stack trace: #0 /in/gRMRp(11): {closure}() #1 {main} thrown in /in/gRMRp on line 8
Process exited with code 255.
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33
o Fatal error: Uncaught Error: Function name must be a string in /in/gRMRp:8 Stack trace: #0 /in/gRMRp(11): {closure}() #1 {main} thrown in /in/gRMRp on line 8
Process exited with code 255.
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40
Parse error: syntax error, unexpected '(' in /in/gRMRp on line 11
Process exited with code 255.

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