A word w1 is a prefix of another w2 if there is a word w such that w2 = w1w where the product is concatenation. For example, w1 = 0110 is a prefix of w2 = 0110101 with w = 101.
(of a string α) Any string β where α is the concatenation βγ for some string γ. Thus in coding theory, a word is said to be a prefix of another word if the former word matches the first symbols of the latter. See also prefix codes.
The sequence of quantifiers and variables appearing in a formula in prenex normal form. For example, for a first-order formula of the form:
• Q0x0...Qn−1xn−1φ
where each Qi is a universal or existential quantifier, the prefix of the formula is the sequence 〈Q0x0...Qn−1xn−1〉.
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