title: Conditionally Validation in Yup
body: <p>How to implement the condition like value of 1 field should always be greater than the value of another field.</p>
  
  <p>here's my schema</p>
  
  <pre><code>   value: Yup.number().required(''),
     value2: Yup.number().when('value',{
       is: (val) =&gt; something here
      then: Yup.number().required('Required').positive('value should be positive'),
      otherwise: Yup.number()
    })
  </code></pre>
  
  <p>I want to check for value2 to always be > value. 
  How to access value2's value in the when condition?</p>