Example
{ x = X ^ y = Y }t := x; x := y; y := t{ x = Y ^ y = X }
Compute intermediate assertions
- { x = X ^ y = Y }t := x; { x = X ^ y = Y ^ t = X }x := y{ x = Y ^ y = Y ^ t = X }y := t{ x = Y ^ y = X ^ t = X }
{ x = Y ^ y = X ^ t = X } => { x = Y ^ y = X }