((input
  (VAR . "GEMVER")
  (param_list
   (param (VAR . "A") (type (orientation . "column")))
   (param_list
    (param (VAR . "u1") (type . "vector"))
    (param_list
     (param (VAR . "u2") (type . "vector"))
     (param_list
      (param (VAR . "v1") (type . "vector"))
      (param_list
       (param (VAR . "v2") (type . "vector"))
       (param_list
        (param (VAR . "a") (type . "scalar"))
        (param_list
         (param (VAR . "b") (type . "scalar"))
         (param_list
          (param (VAR . "y") (type . "vector"))
          (param_list (param (VAR . "z") (type . "vector")))))))))))
  (param_list
   (param (VAR . "B") (type (orientation . "column")))
   (param_list
    (param (VAR . "x") (type . "vector"))
    (param_list (param (VAR . "z") (type . "vector")))))
  (prog
   (prog
    (prog
     (stmt
      (VAR . "B")
      (expr
       (expr
        (expr (VAR . "A"))
        (expr (expr (VAR . "u1")) (expr (expr (VAR . "v1")))))
       (expr (expr (VAR . "u2")) (expr (expr (VAR . "v2")))))))
    (stmt
     (VAR . "x")
     (expr
      (expr
       (expr (VAR . "b"))
       (expr (expr (expr (expr (VAR . "B"))) (expr (VAR . "y")))))
      (expr (VAR . "z")))))
   (stmt
    (VAR . "w")
    (expr
     (expr (VAR . "a"))
     (expr (expr (expr (VAR . "B")) (expr (VAR . "x")))))))))