(define-syntax CaseMettaMatch
  (syntax-rules (else)
    ((_ var ((pat body) ...))
     (case var ((pat) body) ...))))
     
(define-syntax CaseMettaNoMatch
  (syntax-rules ()
    ((_ var ((p body1) ... (elsemaybe elsebody)))
     (if (eq? 'elsemaybe 'else)
         'elsebody))))

(define-syntax CaseMetta
  (syntax-rules ()
    ((_ var cases)
      (let ((z (CaseMettaMatch var cases)))
           (if (eq? (if #f 1) z)
               (CaseMettaNoMatch var cases) z)))))

(display (CaseMetta 343 ((1 2) (3 4) (5 6) (else 42) )))
;42

(display (CaseMetta 343 ((1 2) (3 4) (5 6) (asdasd 42) )))
;unspecified

(display (CaseMetta 3 ((1 2) (3 4) (5 6) (asdasd 42) )))
;4