rror: (=) bad argument type - not a number: (p)

        Call history:

        <syntax>          [reverse] (* (expt 10 (car x)) (cadr x))
        <syntax>          [reverse] (expt 10 (car x))
        <syntax>          [reverse] (car x)
        <syntax>          [reverse] (cadr x)
        <syntax>          [reverse] (zip (iota (length rns)) rns)
        <syntax>          [reverse] (iota (length rns))
        <syntax>          [reverse] (length rns)
        <syntax>          [reverse] (_inner n (quote ()))
        <syntax>          [reverse] (quote ())
        <syntax>          [reverse] (##core#quote ())
        <syntax>          [reverse] (##core#undefined)
        <syntax>          (define (palinpalin? p) (eqv? p (reverse p)))
        <syntax>          (##core#set! palinpalin? (##core#lambda (p) (eqv? p (reverse p))))
        <syntax>          (##core#lambda (p) (eqv? p (reverse p)))
        <eval>    [reverse] (_inner n (quote ()))
        <eval>    [_inner] (= 0 k)      <--