{{# or([EXPRESSION...]) }} TRUTHY {{else}} FALSY {{/ or }}

or( x, y ) works just like x || y. You can use it directly within a magic tag like:

import {stache} from "can";

var view = stache(`{{# or(this.x, this.y) }} YES {{else}} NO {{/ or }}`);

var fragment = view({ x: 0, y: true});
console.log(fragment.firstChild.nodeValue) //-> YES
document.body.append(fragment);

You can use or in a nested expression like:

{{# if( or(this.x, this.y) ) }} YES {{else}} NO {{/ or }}

It also takes multiple arguments. or( x, y, z ) works just like x || y || z.