Function num_q 

pub fn num_q(ns: Option<&str>, name: &str, canonical: &str) -> Expr

A number value whose domain may be namespace-qualified. num_q(None, name, canonical) is identical to num; num_q(Some(ns), name, canonical) emits a qualified domain symbol (for example numbers/f64). Use this when a caller must preserve an existing qualified number domain rather than the unqualified spelling produced by float or num.