Sample single line presentation of HOTVX set. HOTV is suitable for 3 to 5 years of age, HOTVX for 3 to 5, HOTVXLA for 4 to 5 and HOTVXLACU for 5 to 7. See also lower case for children. Letters and symbols can be presented in numerous ways: random, pseudo random, with/without repeats, single character, single line, dual line, multiple line, duochrome and stereogram modes; interactively or passively; in variable contrast; inverted; mirrored.