Model-Based vs. Functional Spec: Analysis for Software Testing & Verification - Prof. Step, Study notes of Engineering

Download Model-Based vs. Functional Spec: Analysis for Software Testing & Verification - Prof. Step and more Study notes Engineering in PDF only on Docsity! Model-based vs. Functional Specification Software Testing and Verification Prepared by Stephen M. Thebaut, Ph.D. University of Florida Bonus Review Material Model-based vs. Functional Specification {true} temp := x x := y y := temp {x=y’ y=x’ temp=x’} Function computed by the program ([S]): [S] = (x,y,temp := y,x,x) Is the program “correct”? Comparable specified function (f): f = (x,y,temp := y,x,x) {P} S {Q} ? {P} S {Q} strongly ? f = [S] ? f ⊂ [S] ? A different program… {x>0 y>0} if (x>0 & y>0) then temp := x x := y y := temp end_if Function computed by the program ([S]): (x>0 y>0 → x,y,temp := y,x,x | true → I) {x=y’ y=x’} Comparable specified function (f): (x>0 y>0 → x,y := y,x) Is the program “correct”? {P} S {Q} ? {P} S {Q} strongly ? f = [S] ? f ⊂ [S] ? A really different program… {x>0 y>0} if (x>0 & y>0) then temp := x x := y y := temp else while (1=1) do Function computed by the program ([S]): (x>0 y>0 → x,y,temp := y,x,x) Is the program “correct”? no-op end_while end_if_else {x=y’ y=x’} Comparable specified function (f): (x>0 y>0 → x,y := y,x) {P} S {Q} ? {P} S {Q} strongly ? f = [S] ? f ⊂ [S] ? Pre-condition weakened again {true} if (x>0 & y>0) then temp := x x := y y := temp else while (1=1) do Function computed by the program ([S]): (x>0 y>0 → x,y,temp := y,x,x) Is the program “correct”? no-op end_while end_if_else {x=y’ y=x’} Comparable specified function (f): f = (x,y := y,x) {P} S {Q} ? {P} S {Q} strongly ? f = [S] ? f ⊂ [S] ?