Partial Correctness of a Fibonacci Algorithm

Autor: Artur Korniłowicz
Rok vydání: 2020
Předmět:
Zdroj: Formalized Mathematics, Vol 28, Iss 2, Pp 187-196 (2020)
ISSN: 1898-9934
1426-2630
Popis: Summary In this paper we introduce some notions to facilitate formulating and proving properties of iterative algorithms encoded in nominative data language [19] in the Mizar system [3], [1]. It is tested on verification of the partial correctness of an algorithm computing n-th Fibonacci number: i := 0 s := 0 b := 1 c := 0 while (i <> n) c := s s := b b := c + s i := i + 1 return s This paper continues verification of algorithms [10], [13], [12] written in terms of simple-named complex-valued nominative data [6], [8], [17], [11], [14], [15]. The validity of the algorithm is presented in terms of semantic Floyd-Hoare triples over such data [9]. Proofs of the correctness are based on an inference system for an extended Floyd-Hoare logic [2], [4] with partial pre- and post-conditions [16], [18], [7], [5].
Databáze: OpenAIRE