Infinitive (in indirect discourse).—The tenses of the infinitive in indirect discourse denote the same time relative to that of the leading verb (present, past, or future) as was denoted by the corresponding tenses of the indicative in direct discourse which they represent.
a. The present infinitive represents also the imperfect, the perfect infinitive represents also the pluperfect indicative.
b. The action of the present is usually coincident, that of the aorist anterior, to the action of the leading verb.
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].