In the eddic poem Hrafnagaldur Óðins, stanza 6, Idunn is identified as an "elf" (alfar) and the "youngest of the elder children of Ivaldi." This implies that Ivaldi had two sets of children, probably by different mothers. Thus Idunn is a sister of the famous smiths, the Sons of Ivaldi. In addition to that, according to the Poetic Edda, Tyr is said to the sons of the giants(Jötunn) Hymir and Hroðr. In that case, how and why are these two gods?