Key word signing Key word signing Key word signing is a technique of simultaneous communication whereby the communication partner of the user will use both natural speech and also produce signs for the words that carry the most important information. Key word signing puts emphasis on the pertinent words in a sentence or a phrase, rather than signing every word like you would for American Sign Language (ASL). For example, if someone said, "Go wash your hands" the key words that would be signed would be "wash" and "hand". Key word signing is a form of augmentative and alternative communication (AAC) that uses
Square-free word first difference of the Thue–Morse sequence. That is, from the Thue–Morse sequence one forms a new sequence in which each term is the difference of two consecutive terms of the Thue–Morse sequence. The resulting square-free word is Another example found by John Leech is defined recursively over the alphabet {"a, b, c"}. Let formula_1 be any word starting with the letter "a". Define the words formula_2 recursively as follows: the word formula_3 is obtained from formula_4 by replacing each "a" in formula_4 with , each "b" with , and each "c" with . It is possible to check that the