reg034.idr:6:5:When elaborating left hand side of bar:
When elaborating an application of main.bar:
        Can't unify
                x = x
        with
                length xs = length ys
        
        Specifically:
                Can't unify
                        length ys
                with
                        length xs
reg034.idr:9:5:When elaborating left hand side of foo:
When elaborating an application of main.foo:
        Can't unify
                x = x
        with
                f x = f y
        
        Specifically:
                Can't unify
                        f y
                with
                        f x