-- | Get the 'CoAxiom' from a 'TyThing' if it is a coercion axiom thing. Panics otherwise
tyThingCoAxiom :: TyThing -> CoAxiom Branched
tyThingCoAxiom (ACoAxiom ax) = ax
tyThingCoAxiom :: TyThing -> CoAxiom Branched
tyThingCoAxiom (ACoAxiom ax) = ax
tyThingCoAxiom (ACoAxiom ax) = ax