gistfile1.clj

(cond ; can be hard to tell which is a test and which is a return value
 (zero? (reduce + input-values)) 0
 (empty? (filter #{val1 val2 val3} (map #(foo x (nth % 4))
                                        y)))
 (some #{question answer} (last user-input))
 ...)

(cond    ; looks weird, and leaves a complex last-form in doubt anyway
 (zero? (reduce + input-values))
 0
 (empty? (filter #{val1 val2 val3} (map #(foo x (nth % 4))
                                        y)))
 (some #{question answer} (last user-input))
 ...)

(cond ; what if this were allowed? [...] is never nil, so won't conflict
 (zero? (reduce + input-values)) 0 
 [(empty? (filter #{val1 val2 val3} (map #(foo x (nth % 4))
                                         y)))
  (some #{question answer} (last user-input))]
 ...)