Loop Invariants-Methods of Software Engineering-Lecture Slides, Slides of Software Engineering

Download Loop Invariants-Methods of Software Engineering-Lecture Slides and more Slides Software Engineering in PDF only on Docsity! Loop Invariants s = 0; for i := 1 to n do s = s + a[i]; What is the ‘loop invariant’? s is the sum of elements from a[1] to a[i] immediately before i is incremented! docsity.com Weakest Precondition for While Statement {P} while B do S {Q} • Let W be while B do S • condition for termination of the loop P0  (not B) P1  B and wp(S,P0)  wp(S, not B) Pk  B and wp(S, Pk-1) • wp(W, true)  wp(W, not B)  (k: k  0: Pk) docsity.com