Example of properties so that "any two properties imply the third"
(Not nonmathematical)
In an $n$-dimensional vector space consider the statements about a subset $S$:
- $S$ is independent.
- $S$ spans.
- $S$ has cardinality $n$.
- One dollar is worth $\frac67$ euro.
- One euro is worth $\frac78$ pounds.
- One pound is worth $\frac43$ dollars.