// output of ./demo/comb/binary-sl-gray-demo.cc:
// Description:
//% Binary numbers in a minimal-change order
//% related so subset-lex order ("SL-Gray" order).
//% Representation as delta-sets (binary words).
//% Loopless generation, only O(1) data beyond the array of bits.
//% Cf. OEIS sequence A217262.

arg 1: 6 == n  [Number of digits]  default=6

   0:  [ . . . . . . ]      .1....  1  -    {  }
   1:  [ 1 . . . . . ]      1.....  0  +    { 0 }
   2:  [ 1 1 . . . . ]      .1....  1  +    { 0, 1 }
   3:  [ 1 1 1 . . . ]      ..1...  2  +    { 0, 1, 2 }
   4:  [ 1 1 1 1 . . ]      ...1..  3  +    { 0, 1, 2, 3 }
   5:  [ 1 1 1 1 1 . ]      ....1.  4  +    { 0, 1, 2, 3, 4 }
   6:  [ 1 1 1 1 1 1 ]      .....1  5  +    { 0, 1, 2, 3, 4, 5 }
   7:  [ 1 1 1 1 . 1 ]      ....1.  4  -    { 0, 1, 2, 3, 5 }
   8:  [ 1 1 1 . . 1 ]      ...1..  3  -    { 0, 1, 2, 5 }
   9:  [ 1 1 1 . 1 1 ]      ....1.  4  +    { 0, 1, 2, 4, 5 }
  10:  [ 1 1 1 . 1 . ]      .....1  5  -    { 0, 1, 2, 4 }
  11:  [ 1 1 . . 1 . ]      ..1...  2  -    { 0, 1, 4 }
  12:  [ 1 1 . . 1 1 ]      .....1  5  +    { 0, 1, 4, 5 }
  13:  [ 1 1 . . . 1 ]      ....1.  4  -    { 0, 1, 5 }
  14:  [ 1 1 . 1 . 1 ]      ...1..  3  +    { 0, 1, 3, 5 }
  15:  [ 1 1 . 1 1 1 ]      ....1.  4  +    { 0, 1, 3, 4, 5 }
  16:  [ 1 1 . 1 1 . ]      .....1  5  -    { 0, 1, 3, 4 }
  17:  [ 1 1 . 1 . . ]      ....1.  4  -    { 0, 1, 3 }
  18:  [ 1 . . 1 . . ]      .1....  1  -    { 0, 3 }
  19:  [ 1 . . 1 1 . ]      ....1.  4  +    { 0, 3, 4 }
  20:  [ 1 . . 1 1 1 ]      .....1  5  +    { 0, 3, 4, 5 }
  21:  [ 1 . . 1 . 1 ]      ....1.  4  -    { 0, 3, 5 }
  22:  [ 1 . . . . 1 ]      ...1..  3  -    { 0, 5 }
  23:  [ 1 . . . 1 1 ]      ....1.  4  +    { 0, 4, 5 }
  24:  [ 1 . . . 1 . ]      .....1  5  -    { 0, 4 }
  25:  [ 1 . 1 . 1 . ]      ..1...  2  +    { 0, 2, 4 }
  26:  [ 1 . 1 . 1 1 ]      .....1  5  +    { 0, 2, 4, 5 }
  27:  [ 1 . 1 . . 1 ]      ....1.  4  -    { 0, 2, 5 }
  28:  [ 1 . 1 1 . 1 ]      ...1..  3  +    { 0, 2, 3, 5 }
  29:  [ 1 . 1 1 1 1 ]      ....1.  4  +    { 0, 2, 3, 4, 5 }
  30:  [ 1 . 1 1 1 . ]      .....1  5  -    { 0, 2, 3, 4 }
  31:  [ 1 . 1 1 . . ]      ....1.  4  -    { 0, 2, 3 }
  32:  [ 1 . 1 . . . ]      ...1..  3  -    { 0, 2 }
  33:  [ . . 1 . . . ]      1.....  0  -    { 2 }
  34:  [ . . 1 1 . . ]      ...1..  3  +    { 2, 3 }
  35:  [ . . 1 1 1 . ]      ....1.  4  +    { 2, 3, 4 }
  36:  [ . . 1 1 1 1 ]      .....1  5  +    { 2, 3, 4, 5 }
  37:  [ . . 1 1 . 1 ]      ....1.  4  -    { 2, 3, 5 }
  38:  [ . . 1 . . 1 ]      ...1..  3  -    { 2, 5 }
  39:  [ . . 1 . 1 1 ]      ....1.  4  +    { 2, 4, 5 }
  40:  [ . . 1 . 1 . ]      .....1  5  -    { 2, 4 }
  41:  [ . . . . 1 . ]      ..1...  2  -    { 4 }
  42:  [ . . . . 1 1 ]      .....1  5  +    { 4, 5 }
  43:  [ . . . . . 1 ]      ....1.  4  -    { 5 }
  44:  [ . . . 1 . 1 ]      ...1..  3  +    { 3, 5 }
  45:  [ . . . 1 1 1 ]      ....1.  4  +    { 3, 4, 5 }
  46:  [ . . . 1 1 . ]      .....1  5  -    { 3, 4 }
  47:  [ . . . 1 . . ]      ....1.  4  -    { 3 }
  48:  [ . 1 . 1 . . ]      .1....  1  +    { 1, 3 }
  49:  [ . 1 . 1 1 . ]      ....1.  4  +    { 1, 3, 4 }
  50:  [ . 1 . 1 1 1 ]      .....1  5  +    { 1, 3, 4, 5 }
  51:  [ . 1 . 1 . 1 ]      ....1.  4  -    { 1, 3, 5 }
  52:  [ . 1 . . . 1 ]      ...1..  3  -    { 1, 5 }
  53:  [ . 1 . . 1 1 ]      ....1.  4  +    { 1, 4, 5 }
  54:  [ . 1 . . 1 . ]      .....1  5  -    { 1, 4 }
  55:  [ . 1 1 . 1 . ]      ..1...  2  +    { 1, 2, 4 }
  56:  [ . 1 1 . 1 1 ]      .....1  5  +    { 1, 2, 4, 5 }
  57:  [ . 1 1 . . 1 ]      ....1.  4  -    { 1, 2, 5 }
  58:  [ . 1 1 1 . 1 ]      ...1..  3  +    { 1, 2, 3, 5 }
  59:  [ . 1 1 1 1 1 ]      ....1.  4  +    { 1, 2, 3, 4, 5 }
  60:  [ . 1 1 1 1 . ]      .....1  5  -    { 1, 2, 3, 4 }
  61:  [ . 1 1 1 . . ]      ....1.  4  -    { 1, 2, 3 }
  62:  [ . 1 1 . . . ]      ...1..  3  -    { 1, 2 }
  63:  [ . 1 . . . . ]      ..1...  2  -    { 1 }
 ct=64