Equivocation Example

The Equivocation Fallacy, in which a logical error occurs when a word (or phrase) with two meanings is used in a confusing manner:

Margarine is better than nothing.
Nothing is better than butter.
Therefore, margarine is better than butter.

H/t: James Taranto

Here’s a similar one, based on the Fallacy of Four Terms:

Nothing is better than eternal happiness.
A ham sandwich is better than nothing.
Therefore, a ham sandwich is better than eternal happiness.