DataExpr::Lambda { variables, body } => write!(f, "(lambda {} . {})", variables.iter().format(", "), body),
DataExpr::SetBagComp { variable, predicate } => write!(f, "{{ {variable} | {predicate} }}"),
DataExpr::Whr { expr, assignments } => write!(f, "{} whr {} end", expr, assignments.iter().format(", ")),