False equivalence is a logical fallacy which describes a situation where there is a logical and apparent equivalence, but when in fact there is none. It would be the antonym of the mathematical concept of material equivalence. It is achieved by "shifting, imprecise, or tactical (re)definition of a linking term.
A common way for this fallacy to be perpetuated is one shared trait between two subjects is assumed to show equivalence, especially in order of magnitude, when equivalence is not necessarily the logical result. The pattern of the fallacy is often as such: If A is the set of c and d, and B is the set of d and e, then since they both contain d, A and B are equal. It should be noted though that d existing in both sets is not required, only a passing similarity is required to cause this fallacy to be able to be used.