data specification
using checksum
,
volid
data types avidheader := empty
| garbage
| avidhdr(. .vol : volid;
. .leb : nat;
. .sqn : nat;
. .size : nat;
. .checksum : nat) with .valid?
;
variables avhdr : avidheader;
avhdr0 : avidheader;
avhdr1 : avidheader;
end data specification