1. The problem statement, all variables and given/known data Let [itex]H[/itex] be a connected Lie group with Lie algebra [itex]\mathfrak h[/itex] such that [itex][\mathfrak h, \mathfrak h] = 0[/itex]. Show that: [itex]\exp: \mathfrak h \rightarrow H[/itex] is the covering homomorphism. --------- I am not really sure what I have to show here, specifically I don't know what they mean by "the covering homomorphism" which to me implies uniqueness but I can't find a theorem which implies that there exists a unique covering homomorphism in the given case. Or maybe I'm merely supposed to show that this is both a homomorphism and a covering?