         }
         
         do {
+            parsed = try Interpreter.parse("(cosh a)")
+            let _ = try Interpreter.eval(&parsed, with: &interpreter.globalEnv)
+            XCTFail()
+        } catch {
+            XCTPass()
+        }
+        
+        do {
             parsed = try Interpreter.parse("(cosh 1.0 1.0)")
             let _ = try Interpreter.eval(&parsed, with: &interpreter.globalEnv)
             XCTFail()

        }
        
        do {
            parsed = try Interpreter.parse("(tanh 1.0 1.0)")
            let _ = try Interpreter.eval(&parsed, with: &interpreter.globalEnv)
            XCTFail()

        }
        
        do {
            parsed = try Interpreter.parse("(atanh a)")
            let _ = try Interpreter.eval(&parsed, with: &interpreter.globalEnv)
            XCTFail()
        } catch {
