var nt = ntype.n_types[i]
var mt = resolve_mtype(mmodule, mclassdef, nt)
if mt == null then return null # forward error
var anchor
if mclassdef != null then anchor = mclassdef.bound_mtype else anchor = null
if not check_subtype(nt, mmodule, anchor, mt, bound) then
var nt = ntype.n_types[i]
var mt = resolve_mtype(mmodule, mclassdef, nt)
if mt == null then return null # forward error
var anchor
if mclassdef != null then anchor = mclassdef.bound_mtype else anchor = null
if not check_subtype(nt, mmodule, anchor, mt, bound) then