 
 		case let .Annotation(term, type):
 			return "\(term) : \(type)"
+
+		case let .Axiom(v, type):
+			return "'\(v) : \(type)"
 		}
 	}
 

			return ifIf(a, b, c)
		case let .Annotation(term, type):
			return ifAnnotation(term, type)
		}
	}


				ifProjection: Expression.Projection,
				ifProduct: Expression.Product,
				ifIf: Expression.If,
				ifAxiom: Expression.Axiom,
				otherwise: const(t)))
		} (Recur(self)).out
	}
