synonym type not allowed

[Erik Zuurbier]

:: MyType :== (Int,Real)

instance == MyType
where   (==) (i1,r1) (i2,r2)    = i1==i2 && r1==r2
        (==) _ _                = False

This gives:
Error [Tryit.icl,17,==]: MyType type synonym used as instance

Will type synonyms be allowed here in a future version of the Clean
compiler, or is there some fundamental reason to disallow them?

I 'solve' the problem by writing:

instance == (Int,Real)
where   ....

but that is not why we have type synonyms.