Go backward to ExampleGo up to TopGo forward to Total Order |

*Definition:* Two elements `x` and `y` are *incomparable*
with respect to a relation **<=** if neither `x` **<=** `y`
nor `y` **<=** `x`:

xandyare incomparable w.r.t.<=: <=>xnot<=y/\ynot<=x.

*Example:*
{0, 1} and {1, 2} are incomparable w.r.t. subset .

Author: Wolfgang Schreiner

Last Modification: January 18, 2000