How to validate nested sequence?

[glyh]

I'm trying to write a recursive descendent parser with malli, here's what I have:

(defn lit= [c]
  [:fn (partial = c)])
(def let-schema  [:cat (lit= 'let) [:+ [:cat symbol? :any]] :any])

However, the schema will not work because it matches (let a 1 b 2 (+ a b)) instead of (let [a 1 b 2] (+ a b), how should I fix it? Thank you!

EDIT: I tried provider with no good result:

(mp/provide
  '(let [a 1 b 2] a)
  '(let [x 3] 3))

[glyh]

Solved:
[:catn [:_ [:= 'defn]] [:name :symbol] [:bindings [:vector :symbol]] [:exp :any]]