Отметить Checkbox при условии (чистый js)

document.getElementById('dva').addEventListener('change', function() { 
  document.getElementById('odin').checked = !document.getElementById('dva').checked; 
}); 
 
document.getElementById('odin').addEventListener('change', function() { 
  document.getElementById('dva').checked = !document.getElementById('odin').checked; 
});

<label for="odin">Odin</label> 
<input type="checkbox" id="odin" /> 
<br /> 
<label for="dva">Dva</label> 
<input type="checkbox" id="dva" />

var chckbx = document.querySelectorAll('input[type="checkbox"]'); 
 
Array.from(chckbx).forEach(function (chck) { 
  chck.addEventListener('change', function (e) { 
    Array.from(chckbx).forEach(function (chck) { 
      chck.checked = false; 
    }); 
     
    e.target.checked = true; 
  }); 
});

input[type="checkbox"]:checked + label { 
  color: #0f0; 
}

<input type="checkbox" id="odin"> 
<label for="odin">Odin</label> 
<br> 
<input type="checkbox" id="dva"> 
<label for="dva">Dva</label>