- x : 9..11 \desdak x : Int ∧9 \leqslant x \leqslant 11
- f(x:9..11) : 3..5 {…}
int f(int x) {
require( 9 <= x && x <= 11 );
...
promise( 3 <= result && result <= 5);
return result;
}
int f(int x) {
require( 9 <= x && x <= 11 );
...
promise( 3 <= result && result <= 5);
return result;
}