Making an invertible function out of non-invertible parts
This is a weird headline. It amounts to the claim that <i>f</i>(<i>x</i>) = <i>x</i> + 3 is made from non-invertible parts because its &quot;subcomponent&quot; <i>g</i>(<i>x</i>) = 3 is non-invertible.<p>But who cares? Our <i>f(x)</i> is as conceptually simple as an invertible function can be. If we&#x27;re going to consider it to have been assembled from non-invertible parts, then what&#x27;s interesting about the fact that an invertible function can be assembled from non-invertible parts? It&#x27;s impossible to define any function, invertible or not, without using non-invertible parts -- by this definition.