[tromp]

Below the truth table for implication (with arguments reversed) they claim

> It turns out this truth table is functionally complete [1]

yet the linked Wikipedia article clearly states that

> every two-element set of connectives containing NOT and one of { AND, OR, IMPLY } is a minimal functionally complete subset of { NOT, AND, OR, IMPLY, IFF }. I.e. IMPLY by itself is not functionally complete.

[1] https://en.wikipedia.org/wiki/Functional_completeness

[Epa095]

The article kind of took for granted that you could include the number 0 as well, and with "-0" he got bottom, so its the 2-element set {-->, _|_}.

[gliptic]

The unstated assumption is that you also have FALSE.