A.if really, if indeed, Il.3.25, etc.; esp. even if, even though, Il.7.117, Od.1.167, etc.; “εἴ. καί” 9.35; “εἴ. τε” Il.10.225; “εἴ. γε” A.Ch.198, Pl.Prt.312a, etc.; “εἴ. γε δή” Id.Tht.182c; with words between, εἴ. γάρ τε χόλον γε . . Il.1.81; “εἴπερ ἔσται γε” A.Ag.1249, cf. Pl.Plt.275e; “καλῶς, εἴπερ ποτέ, ἔχει” Th.4.20; “εἴπερ ἄρα” Jul.Or.7.216b.
II. in Att. and Trag. to imply that the supposition agrees with the fact, if as is the fact, since, Th.6.14, etc.; but with impf. it implies that it is contrary to the fact, εἴπερ ἦν πέλας if I had been (but I was not), S.El.312, cf. 604; also εἴ. ἐκτελεῖς ἅπερ λέγεις if only you will keep your word, Id.Ichn.48.
III. with an ellipse, if you must, Ar.Nu.227; ἀλλ᾽ εἴ. but if so, Pl.Prm.150b, Arist.EN1101a12; cf. “εἰ” B. VII.