Lecture notes on Witt vectors
... be the sequences (an | n ∈ S) and (bn | n ∈ S). Since φp is a ring homomorphism, Lemma 1 shows immediately that the sequences w(a) + w(b), w(a) · w(b), and −w(a) are in the image of the ghost map. It follows that there are sequences of polynomials s = (sn | n ∈ S), p = (pn | n ∈ S), and ι = (ιn | n ...
... be the sequences (an | n ∈ S) and (bn | n ∈ S). Since φp is a ring homomorphism, Lemma 1 shows immediately that the sequences w(a) + w(b), w(a) · w(b), and −w(a) are in the image of the ghost map. It follows that there are sequences of polynomials s = (sn | n ∈ S), p = (pn | n ∈ S), and ι = (ιn | n ...
Assignment 7 Properties of operations
... and out comes the output. You are already familiar with many operations: addition, subtraction, multiplication and division are all operations. These four operations each take two numbers as input, and give one number as output. They are called binary operations. ...
... and out comes the output. You are already familiar with many operations: addition, subtraction, multiplication and division are all operations. These four operations each take two numbers as input, and give one number as output. They are called binary operations. ...
![Rings of constants of the form k[f]](http://s1.studyres.com/store/data/021444599_1-2b48e542456bdb5a68a0329bdee50e0a-300x300.png)
