Compute variance of type parameter tparam' in all type arguments
tparams1'.tps which correspond to formal type parameters
Compute variance of type parameter tparam' in type annotation annot'.
Compute variance of type parameter tparam' in all type annotations annots'.
Compute variance of type parameter tparam' in type of symbol sym'.
Compute variance of type parameter tparam' in types of all symbols sym'.
Compute variance of type parameter tparam in type tp.
Compute variance of type parameter tparam' in all types tps'.
Variances form a lattice, 0 <= COVARIANT <= Variances, 0 <= CONTRAVARIANT <= VARIANCES