include::../description.adoc[] == Noncompliant Code Example [source,php] ---- preg_match("/(?=a)b/", $str); // Noncompliant, the same character can't be equal to 'a' and 'b' at the same time ---- == Compliant Solution [source,php] ---- preg_match("/(?<=a)b/", $str); preg_match("/a(?=b)/", $str); ---- ifdef::env-github,rspecator-view[] ''' == Implementation Specification (visible only on this page) include::../message.adoc[] include::../highlighting.adoc[] endif::env-github,rspecator-view[]