`object
method constraint_ : Type.constraint_ -> 'a
method virtual crush : 'a list -> 'a
method decl : Type.decl -> 'a
method expr : Type.expr -> 'a
method field : Type.field -> 'a
method gsummand : Type.gsummand -> 'a
method poly_expr : Type.poly_expr -> 'a
method repr : Type.repr -> 'a
method rhs : Type.rhs -> 'a
method summand : Type.summand -> 'a
method tagspec : Type.tagspec -> 'a
method variant : Type.variant -> 'a
end`