• eir@cis.upenn.edu's avatar
    Refactor handling of decomposition. · 7eceffb3
    eir@cis.upenn.edu authored
    This adds the significant Note [Decomposing equalities] to
    TcCanonical, trying to sort out the various cases involved.
    The only functional change this commit should make is a different
    treatment of data families, which were wrong before (they could
    be decomposed at role R, which is wrong).
OptCoercion.hs 26.6 KB