can-bind.js
function() {
		if (this._bindingState.child === false && this._childToParent === true) {
			var options = this._options;
			this._bindingState.child = true;
			turnOnListeningAndUpdate(options.child, options.parent, this._updateParent, options.queue);
		}
	}
function() {
		if (this._bindingState.child === false && this._childToParent === true) {
			var options = this._options;
			this._bindingState.child = true;
			turnOnListeningAndUpdate(options.child, options.parent, this._updateParent, options.queue);
		}
	}
function ( ) { if ( this . _bindingState . child === false && this . _childToParent === true ) { var options = this . _options ; this . _bindingState . child = true ; turnOnListeningAndUpdate ( options . child , options . parent , this . _updateParent , options . queue ) ; } }
Listen for changes to the child observable and update the parent
Listen for changes to the child observable and update the parent