nph>perl -Mre=debug -e'/^(CP|K[LM]|ME|P[AM]|S[LZ]|WX|YZ)XX1/'
Freeing REx: `","'
Compiling REx `^(CP|K[LM]|ME|P[AM]|S[LZ]|WX|YZ)XX1'
size 62 Got 500 bytes for offset annotations.
first at 2
   1: BOL(2)
   2: OPEN1(4)
   4:   BRANCH(7)
   5:     EXACT <CP>(58)
   7:   BRANCH(21)
   8:     EXACT <K>(10)
  10:     ANYOF[LM](58)
  21:   BRANCH(24)
  22:     EXACT <ME>(58)
  24:   BRANCH(38)
  25:     EXACT <P>(27)
  27:     ANYOF[AM](58)
  38:   BRANCH(52)
  39:     EXACT <S>(41)
  41:     ANYOF[LZ](58)
  52:   BRANCH(55)
  53:     EXACT <WX>(58)
  55:   BRANCH(58)
  56:     EXACT <YZ>(58)
  58: CLOSE1(60)
  60: EXACT <XX1>(62)
  62: END(0)
anchored `XX1' at 2 (checking anchored) anchored(BOL) minlen 5
Offsets: [62]
        1[1] 2[1] 0[0] 2[1] 3[2] 0[0] 5[1] 6[1] 0[0] 7[4] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 11[1] 12[2] 0[0] 14[1] 15[1] 0[0] 16[4] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 20[1] 21[1] 0[0] 22[4] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 0[0] 26[1] 27[2] 0[0] 29[1] 30[2] 0[0] 32[1] 0[0] 33[3] 0[0] 36[0]
Freeing REx: `"^(CP|K[LM]|ME|P[AM]|S[LZ]|WX|YZ)XX1"'