This operator can be called with 1 or 3 arguments.
Called with 1 argument, Supremum(S), rendered sup(S), represents the supremum of the set S. This operator is only defined if S
is a subset of R∪{−∞,+∞}. The supremum does not need to be an element of S
itself; in particular, for an open interval S=(a,b), we have sup(S)=b.
Called with 3 arguments, Supremum(f(x), x, P(x)), rendered P(x)supf(x), represents sup({f(x):P(x)})
where P(x)
is a predicate defining the range of x.
The argument x to this operator defines a locally bound variable. The corresponding predicate P(x)
must define the domain of x
unambiguously; that is, it must include a statement such as x∈S
where S
is a known set. More generally, x can be a collection of variables (x,y,…)
all of which become locally bound, with a corresponding predicate P(x,y,…).
Definitions:
Fungrim symbol | Notation | Short description |
---|---|---|
Supremum | P(x)supf(x) | Supremum of a set or function |
RR | R | Real numbers |
Infinity | ∞ | Positive infinity |
OpenInterval | (a,b) | Open interval |
SetBuilder | {f(x):P(x)} | Set comprehension |
Source code for this entry:
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