# Determine the type parameter bounds for `nclassdef`.
	#
	# In case of error, return `null`.
	#
	# REQUIRE: `nmodule.mmodule != null`
	# REQUIRE: `nclassdef.mclass != null`
	private fun build_a_bound_mtype(nmodule: AModule, nclassdef: AClassdef): nullable MClassType
	do
		var mmodule = nmodule.mmodule.as(not null)
		var mclass = nclassdef.mclass.as(not null)

		var bounds = new Array[MType]
		if nclassdef isa AStdClassdef and mclass.arity > 0 then
			var objectclass = try_get_mclass_by_name(nmodule, mmodule, "Object")

			# Revolve bound for formal parameters
			for i in [0..mclass.arity[ do
				if nclassdef.n_formaldefs.is_empty then
					# Inherit the bound
					var bound = mclass.intro.bound_mtype.arguments[i]
					bounds.add(bound)
					continue
				end

				var nfd = nclassdef.n_formaldefs[i]
				var pname = mclass.mparameters[i].name
				if nfd.n_id.text != pname then
					error(nfd.n_id, "Error: formal parameter type #{i} `{nfd.n_id.text}` must be named `{pname}` as in the original definition in module `{mclass.intro.mmodule}`.")
				end
				var nfdt = nfd.n_type
				if nfdt != null then
					var bound = resolve_mtype3_unchecked(mmodule, null, null, nfdt, false)
					if bound == null then return null # Forward error
					if bound.need_anchor then
						# No F-bounds!
						error(nfd, "Error: formal parameter type `{pname}` bounded with a formal parameter type.")
					else
						bounds.add(bound)
						nfd.bound = bound
					end
				else if mclass.mclassdefs.is_empty then
					if objectclass == null then
						error(nfd, "Error: formal parameter type `{pname}` unbounded but no `Object` class exists.")
						return null
					end
					# No bound, then implicitely bound by nullable Object
					var bound = objectclass.mclass_type.as_nullable
					bounds.add(bound)
					nfd.bound = bound
				else
					# Inherit the bound
					var bound = mclass.intro.bound_mtype.arguments[i]
					bounds.add(bound)
					nfd.bound = bound
				end
			end
		end

		return mclass.get_mtype(bounds)
	end