Lq

    {qi}: All of the square roots of 1 such that i,j, qi + qj 0.

Thus this is all the square roots of 1 leaving out the additive inverses. For k=2, 1 is the only qi. For k=10, there would be two qi, 1 and ...18751. (Note that you could actually choose any of the square roots of 1 to be your qi's as long as none of them are additive inverses.) For k=30, there are four qi.

    Lq: { r1*q1 + r2*q*2 + ... + rn*qn | ri Lr }

For any number base that's a prime or power of a prime, Lq = Lr . This is because 1 is the only qi.

Addition and multiplication are easy to define for Lq . We will look at L10q as an example.

(a + bq) + (c + dq) = (a + c) + (b + d)q
(a + bq) * (c + dq) = (ac+bd) + (ad+bc)q

Clearly Lq is closed under addition and multiplication. Thus Lq is a commutative ring. Lr is a subring of Lq .

Interesting properties of 1+q:
    (1+q)2 has only 2 square roots
    (1+q)x = 1+q doesn't imply x=1 (for example x=q works)
    (1+q)x = 0 doesn't imply x=0 (for example x=1-q works)

Base 30, we can choose q1=1, q2=...t1q7f1, q3=...dcm58b and q4=...eaprnb. In the following list, we will refer to these as 1, i, j and k.
    i2 = j2 = k2 = 1
    ij = i/j = j/i = k
    ik = i/k = k/i = j
    jk = j/k = k/j = i
    1 has 8 square roots
    rLr has either 0 or 8 square roots
    (1+i)2 has only 4 square roots
    r*(1+i) has either 0 or 4 square roots
    1+i+j+k has only 2 square roots
    r*(1+i+j+k) has either 0 or 2 square roots

Important Properties of Lq

    LQ1: If Lq Lr , then mLq such that 1/mLf .

Thus for number bases that aren't prime or a power of a prime, Lf is not a field.

    LQ2: If Lq Lr , then m,nLq , m0 and n0 such that mn = 0.

Thus for number bases that aren't prime or a power of a prime, Lf is not an integral domain.

One conclusion from this is that division is not necessarily unique for these number bases within Lq .


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© Scott Sherman 1999