arity bug fix
@@ -78,7 +78,7 @@ pub fn add_fact(&mut self, fact: &Term, mut code: Code) {
pub fn add_rule(&mut self, rule: &Rule, mut code: Code) {
let p = self.code.len();
let name = rule.head.0.name().clone();
- let arity = rule.head.1.arity();
+ let arity = rule.head.0.arity();
self.code.append(&mut code);
self.code_dir.insert((name, arity), p);
