Indeterminate string

An indeterminate string over an alphabet $\Sigma$ is a string over $\mathcal{P}(\Sigma)$. More explicitly, were allowed to have subsets of symbols as primitives when forming a word:

Examples

• $A\{G,C\}GGGT\{A,C\}GGGT\{A,T\}AATA\{G,C,T\}$