D:\dev\perl\ver\verbs\win32>..\perl -Mre=debug -e "'hello world' =~ /l.w/"
Compiling REx "l.w"
Final program:
   1: EXACT <l>(3)
   3: REG_ANY(4)
   4: EXACT <w>(6)
   6: END(0)
anchored "l" at 0 (checking anchored) minlen 3
Guessing start of match in sv for REx "l.w" against "hello world"
Found anchored substr "l" at offset 2...
Starting position does not contradict /^/m...
Guessed: match at offset 2
Matching REx "l.w" against "llo world"
   2 <he> <llo world>        |  1:EXACT <l>(3)
   3 <hel> <lo world>        |  3:REG_ANY(4)
   4 <hell> <o world>        |  4:EXACT <w>(6)
                                  failed...
   3 <hel> <lo world>        |  1:EXACT <l>(3)
   4 <hell> <o world>        |  3:REG_ANY(4)
   5 <hello> < world>        |  4:EXACT <w>(6)
                                  failed...
   9 <hello wor> <ld>        |  1:EXACT <l>(3)
  10 <hello worl> <d>        |  3:REG_ANY(4)
  11 <hello world> <>        |  4:EXACT <w>(6)
                                  failed...
Match failed
Freeing REx: "l.w"