The function format is defined, and understands the esacapes ˜ a, ˜ s, ˜ t, ˜ % and ˜ ˜ only. It also implements the additional escape ˜ u for printing lists with hexadecimal values for system debugging. The numerical formats for binary, octal decimal and hexadecimal are only implemented for fixed integers. The treatment of the field sizes in g, e and f formats are very inconsistent.