ambiguous

indicates whether ambiguous code, e.g. A.ambiguous == false, R.ambiguous == true

Note two bit encoding uses A=0, C=1, G=3, T or U = 2

A 65 01000|00|1  0
C 67 01000|01|1  1
G 71 01000|11|1  3
T 84 01010|10|0  2