Is there any way to use Jasmine default matchers within custom matchers?

I have a custom matcher in some Jasmine test specs of the form:

this.addMatchers({
    checkContains: function(elem){
        var found = false;
        $.each( this.actual, function( actualItem ){

            // Check if these objects contain the same properties.
            found = found || actualItem.thing == elem;
        });
        return found;
    }
});

Of course, actualItem.thing == elem doesn't actually compare object contents- I have to use one of the more complex solutions in Object comparison in JavaScript.

I can't help but notice, though, that Jasmine already has a nice object equality checker: expect(x).toEqual(y). Is there any way to use that within a custom matcher? Is there any general way to use matchers within custom matchers?