Lower-bound inferences. A lower-bound inference from a type U for a type V is made as follows:

A lower-bound inference from a type U for a type V is made as follows:

· If V is one of the unfixed X_i then U is added to the set of bounds for X_i.

· Otherwise if U is an array type U_e[…] and V is either an array type V_e[…]of the same rank, or if U is a one-dimensional array type U_e[]and V is one of IEnumerable<V_e>, ICollection<V_e> or IList<V_e> then

o If U_e is known to be a reference type then a lower-bound inference from U_e to V_e is made

o Otherwise an exact inference from U_e to V_e is made

· Otherwise if V is a constructed type C<V₁…V_k> and there is a unique set of types U₁…U_k such that a standard implicit conversion exists from U to C<U₁…U_k> then an exact inference is made from each U_i for the corresponding V_i.

· Otherwise, no inferences are made.

Fixing

An unfixed type variable X_i with a set of bounds is fixed as follows:

· The set of candidate types U_j starts out as the set of all types in the set of bounds for X_i.

· We then examine each bound for X_i in turn: For each bound U of X_i all types U_j to which there is not a standard implicit conversion from U are removed from the candidate set.

· If among the remaining candidate types U_j there is a unique type V from which there is a standard implicit conversion to all the other candidate types, then X_i is fixed to V.

· Otherwise, type inference fails.