Your convoluted theory is pretty ridiculous in the face of Gen 4:1. The fact is the WORD says Adam and Eve had Cain and it is really impossible for you to sit there and spew this tripe!
Btw, I don't see Abel in Adam's geneology either, but I know Adam lived 800 years and had MANY sons and daughters and one of the sons he had he named CAIN.
Who fed you this crappola?
Show me the passage were adam named a son CAIN and first of all we are talking about what happened in th beggining in the beginning of ADAMS life.