.TH Among
.PP
Among a set of values
.SH Signature
.PP
.RS
.nf
among(val: Alpha|AttrName, vals: Set<Alpha>) \-> Predicate
.fi
.RE
.SH Examples
.PP
.RS
.nf
among(:status, [10, 30])
.fi
.RE
.SH Description
.PP
This predicates checks whether \fB\fCval\fR belongs to the set of values \fB\fCvals\fR\&.
.SH Implementation notes
.PP
The set \fB\fCvals\fR may only contain pure values, attribute names are not
supported. Any enumerable of such values is supported in practice, e.g.
an Array literal.