Magic works :)

use re 'debug';
$_ = "one sata two N/A three N/A";


die if (/\bsata\b/i && /\bN\/A\b/ig && /\bN\/A\b/ig) ;
__END__


Compiling REx `\bsata\b'
size 5 Got 44 bytes for offset annotations.
first at 1
   1: BOUND(2)
   2: EXACTF <sata>(4)
   4: BOUND(5)
   5: END(0)
stclass `BOUND' minlen 4
Offsets: [5]
        1[2] 3[4] 0[0] 7[2] 9[0]
Compiling REx `\bN/A\b'
size 5 Got 44 bytes for offset annotations.
first at 1
   1: BOUND(2)
   2: EXACTF <N/A>(4)
   4: BOUND(5)
   5: END(0)
stclass `BOUND' minlen 3
Offsets: [5]
        1[2] 3[3] 0[0] 6[2] 8[0]
Compiling REx `\bN/A\b'
size 5 Got 44 bytes for offset annotations.
first at 1
   1: BOUND(2)
   2: EXACTF <N/A>(4)
   4: BOUND(5)
   5: END(0)
stclass `BOUND' minlen 3
Offsets: [5]
        1[2] 3[3] 0[0] 6[2] 8[0]
Matching REx `\bsata\b' against `one sata two N/A three N/A'
Matching stclass `BOUND' against `one sata two N/A three '
  Setting an EVAL scope, savestack=3
   0 <> <one sata two>    |  1:  BOUND
   0 <> <one sata two>    |  2:  EXACTF <sata>
                            failed...
  Setting an EVAL scope, savestack=3
   3 <one> < sata two>    |  1:  BOUND
   3 <one> < sata two>    |  2:  EXACTF <sata>
                            failed...
  Setting an EVAL scope, savestack=3
   4 <one > <sata two>    |  1:  BOUND
   4 <one > <sata two>    |  2:  EXACTF <sata>
   8 < sata> < two N/>    |  4:  BOUND
   8 < sata> < two N/>    |  5:  END
Match successful!
Matching REx `\bN/A\b' against `one sata two N/A three N/A'
Matching stclass `BOUND' against `one sata two N/A three N'
  Setting an EVAL scope, savestack=3
   0 <> <one sata two>    |  1:  BOUND
   0 <> <one sata two>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
   3 <one> < sata two>    |  1:  BOUND
   3 <one> < sata two>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
   4 <one > <sata two>    |  1:  BOUND
   4 <one > <sata two>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
   8 < sata> < two N/>    |  1:  BOUND
   8 < sata> < two N/>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
   9 <sata > <two N/A>    |  1:  BOUND
   9 <sata > <two N/A>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
  12 <a two> < N/A th>    |  1:  BOUND
  12 <a two> < N/A th>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
  13 < two > <N/A thr>    |  1:  BOUND
  13 < two > <N/A thr>    |  2:  EXACTF <N/A>
  16 <o N/A> < three >    |  4:  BOUND
  16 <o N/A> < three >    |  5:  END
Match successful!
Matching REx `\bN/A\b' against ` three N/A'
Matching stclass `BOUND' against ` three N'
  Setting an EVAL scope, savestack=3
  16 <o N/A> < three >    |  1:  BOUND
  16 <o N/A> < three >    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
  17 < N/A > <three N>    |  1:  BOUND
  17 < N/A > <three N>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
  22 </A three> < N/A>    |  1:  BOUND
  22 </A three> < N/A>    |  2:  EXACTF <N/A>
                            failed...
  Setting an EVAL scope, savestack=3
  23 </A three > <N/A>    |  1:  BOUND
  23 </A three > <N/A>    |  2:  EXACTF <N/A>
  26 </A three N/A> <>    |  4:  BOUND
  26 </A three N/A> <>    |  5:  END
Match successful!
Died at same.regex.twice.pl line 5.
Freeing REx: `"\\bsata\\b"'
Freeing REx: `"\\bN/A\\b"'
Freeing REx: `"\\bN/A\\b"'
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