### TAU-INTERVAL-HI-REL

access the upper bound relation of a tau interval
Major Section: TAU-SYSTEM

It is the case that

(tau-interval-hi-rel (make-tau-interval dom lo-rel lo hi-rel hi)) = hi-rel

For a well-formed interval, `hi-rel`

is a Boolean, where `t`

denotes the `<`

(strong inequality or ``less-than'') relation and
`nil`

denotes `<=`

(weak inequality or ``less-than-or-equal'') relation
between the elements of the interval and the upper bound.

When the domain of an interval is `INTEGERP`

, there are additional
constraints on the other components. See make-tau-interval.