### 10.3.6 Breaking out a loop

If your program is running a loop and you want it to exit the loop without finishing it, you can use the break command. For example, you can define a program

      testbreak(a,b) := {
      local r;
      while (true) {
        if (b == 0) {break;}
        r := irem(a,b);
        a := b;
        b := r;
      }
      return a;
      }

If you then enter

testbreak(4,0)

it will return

4

since the while loop is interrupted when b is 0 and a is 4.