ASN.1 help please

[Nigel.Head@REDACTED]

I'm attempting to compile a largeish chunk of an ASN.1 spec and am running into
problems. The spec apparently compiles OK with other compilers (although I don't
have any around to prove this to myself, so it's only hearsay).

I've managed to reproduce the problem with a toy source file; as I'm an ASN.1
utter beginner I'd appreciate help as to what is wrong with this so that I can
make the corrections to the real thing (which is a bit large to bother you all
with !!).


=================== source file =================

TEST
DEFINITIONS
::= BEGIN

Thing ::= INTEGER
{    fred (0)
,    fred2     (1)
,    fred3     (2)
}

AnotherThing ::= Thing
(    fred
|    fred2
)


END

=================== error message ==============

(N1@REDACTED)5> asn1ct:compile('TEST').
Erlang ASN.1 version "1.4.2" compiling "TEST.asn1"
Compiler Options: []
asn1error:10:'TEST':'AnotherThing' {asn1,{undefined_type_or_value,fred}}
{error,{asn1,[{error,{type,10,
                           'TEST',
                           'AnotherThing',
                           {asn1,{undefined_type_or_value,fred}}}}]}}


 N.