maybe some stuff foo maybe some more stuff;

##</code><code>##

// maybe some stuff foo maybe some more stuff;

##</code><code>##

$a="abcdefghijklm";
1 print "match" if ( $a =~ /(?<!cde).*?jkl/ );	# match because a does not match cde, then bcdefghi follows, then jkl matches?
2 print "match" if ( $a =~ /(?<=cde).*?jkl/ );	# match because cde matches then fgh follws, then jkl matches

$a="xyzfghijklm";
1 print "match" if ( $a =~ /(?<!cde).*?jkl/ );	# match because cde is not before jkl, then jkl matches
2 print "match" if ( $a =~ /(?<=cde).*?jkl/ );	# no match because cde is not before jkl

##</code><code>##

$a = "mlkjihgfedcba";
print "match" if ( $a =~ /lkj(?!.*?edc/ );	# no match because edc DOES follow lkj. This is what is desired. (It does not match in the unreversed when cde precedes jkl)

$a = "mlkjihgfzyx";
print "match" if ( $a =~ /lkj(?!.*?edc/ );	# match because edc does not follow lkj. Again, this is what I want. ( It does match jkl in the unreversed when not preceded by cde)