--- a/progs/catastrophic.java	Mon Jul 27 01:55:05 2020 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,45 +0,0 @@
-// A case of catastrophic backtracking in Java 8
-//-----------------------------------------------
-//
-// regexp: (a*)*b
-// strings: aa....
-//
-// compile:    javac catastrophic.java
-// call with:  java catastrophic
-//
-// IMPORTANT: 
-// Java 9 improved its regex matching engine.
-// This example is now much faster.
-//
-
-import java.util.regex.*;
-
-public class catastrophic {
-    public static void main(String[] args) {
-	
-        //we always run all the tests twice -> to warmup of the JVM
-        for (int runs = 0; runs < 2; runs++) {
-            
-            Pattern pattern = Pattern.compile("(a*)*b");
-            
-            // Run from 5 to 28 characters
-            for (int length = 5; length < 28; length++) {
-                
-                // Build input of specified length
-                String input = "";
-                for (int i = 0; i < length; i++) { input += "a"; }
-                
-                // Measure the average duration of two calls...  
-                long start = System.nanoTime();
-                for (int i = 0; i < 2; i++) {
-                    pattern.matcher(input).find();
-                }
-
-                // Print out time
-                System.out.println(length + " " + input + ": " 
-                       + ((System.nanoTime() - start) / 2000000000d) 
-                       + "s");
-            }
-        }
-    }
-}