BEFORE & AFTER       REGEX
<>  <A01234567890A>  A
<A>  <01234567890A>  [^AB]*
<A01234567890>  <A>  .
<A01234567890A>  <>  B       FAILED
<A0123456789>  <0A>  .
<A01234567890>  <A>  B       FAILED