 Intuitionistic mathematics, INT, diverges from other types of constructive mathematics in its interpretation of the term “sequence”. Normally, a sequence in constructive mathematics is given by a rule which determines, in advance, how to construct each of its terms; such a sequence may be said to be lawlike or predeterminate. Brouwer generalised this notion of a sequence to include the possibility of constructing the terms one-by-one, the choice of each term being made freely, or subject only to certain restrictions stipulated in advance. Most manipulations of sequences do not require that they be predeterminate, and can be performed on these more general free choice sequences.