Hasse diagram

Meaning

Noun

• A diagram which represents a finite poset, in which nodes are elements of the poset and arrows represent the order relation between elements. Transitivity of the order relation is tacit, in other words, if $x\; \backslash le\; y$ and $y\; \backslash le\; z$ then no arrow is drawn from x to z, but if there is no distinct z between x and y (such that $x\; \backslash le\; z\; \backslash le\; y$) then an arrow is draw from x to y.

Origin

• Named after Helmut Hasse (1898–1979), though he was not the first to use them.