The subjunctive of exhortation, prohibition, or deliberation, the optative of wish, and the imperative, may be used as the apodosis of
εἰ with the indicative in Simple Present and Past conditions ( cross2300 c, d, f),
εἰ with the future indicative in Emotional Future conditions ( cross2328),
ἐά_ν with the subjunctive in More Vivid Future conditions ( cross2326 c-e).
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].