(We don't really know what Chalker 'considers' given that her words are interpreted, not quoted.)
Originally Posted by fivejedjon
What we do know is that the mandative subjunctive has an alternative, putative 'should', also called mandative 'should', 'a periphrastic alternant to the non-inflected subjunctive (ref)'. What's unclear is whether 'alternative' and 'alternant' mean variant, that is, that 'should' expresses the subjunctive mood. According to somebody, it does (Note, I can't seem to find the original source for this):
The subjunctive mood can be expressed using the modal verbs 'shall' (should) and 'may' (might).
★ '''Should the teacher come', I will speak with him.''