Determine if a value range expression is a single value.

vreIsSingleValue is a utility function that returns `TRUE` if the specified value range expression is either numeric, a number expressed as text or an expression of the form "v=" or "v==".

vreIsSingleValue(vre)

Arguments

vre

The value range expression to examine.

Value

`TRUE` if vre is a single value, `FALSE` otherwise.