A chain of `if`/`elsif` statements is evaluated from top to bottom. At most, only one branch will be executed: the first one with a condition that evaluates to `true`.

Therefore, duplicating a condition automatically leads to dead code. Usually, this is due to a copy/paste error. At best, it's simply dead code and at worst, it's a bug that is likely to induce further bugs as the code is maintained, and obviously it could lead to unexpected behavior.

## Noncompliant Code Example

    IF (param = 1) THEN
      open();
    ELSIF (param = 2) THEN
      close();
    ELSIF (param = 1) THEN // Incorrect
      move();
    END IF;

## Compliant Solution

    IF (param = 1) THEN
      open();
    ELSIF (param = 2) THEN
      close();
    ELSIF (param = 3) THEN
      move();
    END IF;