The map can be obtained as a homomorphism on the Bernoulli process. Let formula_7 be the set of all semi-infinite strings of the letters formula_8 and formula_9. These can be understood to be the flips of a coin, coming up heads or tails. Equivalently, one can write formula_10 the space of all (semi-)infinite strings of binary bits. The word "infinite" is qualiified with "semi-", as one can also define a different space formula_11 consisting of all doubley-infinite (double-ended) strings; this will lead to the Baker's map. The qualification "semi-" is dropped below.