Template Haskell fails to recognize type operator/function +

The following message is issued for a valid TH program.

Main.hs:7:1:
    Illegal type constructor or class name: `+'
    When splicing a TH declaration:
      type instance GHC.TypeLits.+ 1 2 = 3
Failed, modules loaded: Test1.

Code attached.

The program is attempting to capture the name +, as used by Nat at the type level.

The problem appears to be in Convert.hs

 -- Convert.hs

     okOcc :: OccName.NameSpace -> String -> Bool
     okOcc _ [] = False 
     okOcc ns str@(c:_) | OccName.isVarNameSpace ns = startsVarId c || startsVarSym c
                        | otherwise = startsConId c || startsConSym c || str == "[]"

• is rejected, by okOcc, even though it is acceptable, the symbol neither starts with upper-case, or ':'.

I have tried using reify to extract the *actual* name from other sources (rather than use mkNameG_tc), and it fails in the same way.

Trac metadata

Trac field	Value
Version	7.6.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Template Haskell
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