title: PromQL If condition and or operator
body: <p>in PromQL, I want to write</p>
  <pre><code>If metric_a&gt;=bool 3:
    return metric_b
  else:
    return 1
  </code></pre>
  <p>I am thinking to write as</p>
  <pre><code>(metric_b and metric_a&gt;=3) or metric_a&lt;bool 3
  </code></pre>
  <p>but I found that when I switch the metric order, like A or B, B or A, the query result would change, also am not sure if what I have means my if-else
  why the or/and operator would give inconsist result? also what is a best way to present the if-else statement in here?</p>