uot;world&quot;)

var greeting = stream.merge([a, b]).map(function(values) {
    return values.join(&quot; &quot;)
})

console.log(greeting()) // logs &quot;hello world&quot;</code></pre>
<p>Or you can use the helper function <code>stream.lift()</code></p>
<pre><code class="language-javascript">var a = stream(&quot;hello&quot;)
var b = stream(&quot;world&quot;)

var greeting = stream.lift(function(_a, _b) {
    return _a + &quot; &quot; + _b
}, a, b)

console.log(greeting()) // logs &quot;hello world&quot;<