• Robbert Krebbers's avatar
    Make nclose an explicit coercion. · bf6caa7f
    Robbert Krebbers authored and Ralf Jung's avatar Ralf Jung committed
    We do this by introducing a type class UpClose with notation ↑.
    The reason for this change is as follows: since `nclose : namespace
    → coPset` is declared as a coercion, the notation `nclose N ⊆ E` was
    pretty printed as `N ⊆ E`. However, `N ⊆ E` could not be typechecked
    because type checking goes from left to right, and as such would look
    for an instance `SubsetEq namespace`, which causes the right hand side
    to be ill-typed.