ImplicitSearch

All available implicits, without ranking

Find a unique best implicit reference

Check if the supplied candidate implicit and target type indicate a diverging implicit search.

Return the reference, if any, to a term under construction or already constructed in the current search history corresponding to the supplied target type.

A term is eligible if its type is a subtype of the target type and either it has already been constructed and is present in the current implicit dictionary, or it is currently under construction and is separated from the current search context by at least one by name argument position.

Note that because any suitable term found is defined as part of this search it will always be effectively in a more inner context than any other definition provided by explicit definitions. Consequently these terms have the highest priority and no other candidates need to be considered.

Try to type-check implicit reference, after checking that this is not a diverging search

Fields needed for divergence checking