isRepStr '1001110011'
1
   Tests=: noun define
1001110011
1110111011
0010010010
1010101010
1111111111
0100101101
0100100
101
11
00
1
)
   isRepStr;._2 Tests     NB. run all tests
1 1 1 1 1 0 1 0 1 1 0