New Twiddle

controllers.application\.js

import Controller from '@ember/controller';
import { and, or } from '@ember/object/computed';

export default Controller.extend({
	isA: 'true',
  isB: and('isA'),
 
  
  actions: {
  	updateProperty(property) {
    	this.set(property, 'false');
    }
  }
});

templates.application\.hbs

<p>Open console</p>

isA {{isA}}
<br>
isB {{isB}}
<br>
<button onclick={{action "updateProperty" "isB"}}>Update isB</button>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}