Hi team,

I have written a trigger to update status on case
Note : If none of apporval not accept case status need to became reject

trigger updatestaus1 on Case_Approval_Tracker__c(after update) {Set <ID> case_ids = new Set <ID>();
 for(Case_Approval_Tracker__c c : Trigger.new) {
  case_ids.add(c.caseid);
 }

 List <Case> caList = [SELECT Id, Status, (SELECT Id,Approval_Status__c FROM Case_Approval_Tracker__c) FROM Case WHERE Id IN : case_ids];

 for(Case a : caList){
   integer count=0;
   for(Case_Approval_Tracker__c c : a.Case_Approval_Tracker__c ){
    if(c.Approval_Status__c == 'Approved'){
     a.Status = 'Approved';
    }
    else{
     a.Status = 'Rejected';  
   }  
   if(a.Case_Approval_Tracker__c.size()==count){
       a.Status = 'Rejected';
   }

  }
  update caList;
}
}


Error :  
(SELECT Id,Approval_Status__c FROM Case_Approval_Tracker__c) FROM Case
                                   ^
ERROR at Row:1:Column:55
Didn't understand relationship 'Case_Approval_Tracker__c' in FROM part of query call. If you are attempting to use a custom relationship, be sure to append the '__r' after the custom relationship name. Please reference your WSDL or the describe call for the appropriate names.

Help me to fix error :)