digit/number: dual ε of dual number in linear algebra; square root of 0
ε2=0 so ε is nilpotent. Acts as a number punctuation mark (separating the real and the dual parts of a dual number); normally prefixed with lau. See also ri'o, ka'o.
x1 (letteral: la'e zo BY/word-bu) is a hyphen/joining letter(al) in language x2 with function in/context of use/with rules for use/with properties x3, joining prefixed unit/lexeme/morpheme/string x4 (quote) to postfixed unit/lexeme/morpheme/string x5 (quote) in construct (full word) x6 (quote)
xl1 (la'e zo BY/word-bu) is a fingerspelling sign in character-set of sign language/system of manual communication xl2 representing letter/digit/symbol xl3=l1 in written alphabet/character-set xl2 performed by hand(s) xl4.
x1 (brivla/selbri) is used by place x2 (number/me'o+FA+bu) being filled with (a description of / symbol for) x3, in the usage of x4, according to rule(s) x5.