I'm in trouble in understanding these two statements in Morita's Geometry of Characteristic Classes book:
First:
what's up with the "twisted" product $K(\pi_2(X),2)\times_{k^4} K(\pi_3(X),3)\cdots\times \cdots$? How is it defined?
Second:
Is $\mathbb Q[\iota]$ the polynomial ring in the "variable"/cohomology class $\iota$? And what about $E_\mathbb Q(\iota)$: in which sense it is "the exterior algebra" over $\mathbb Q$?
I strongly suspect that the problem is "mine" in the sense that I'm not really into these topics. Any kind of reference is appreciated!