The Jacobson Radical of a Semiring" in These PROCEEDINGS, 37, 163-170 (1951) Is in Part Incorrect
462 ERRATA PROC. N. A. S. ERRA TA Dr. R. E. Johnson has called to my attention that Theorem 1 of my paper "The Jacobson Radical of a Semiring" in these PROCEEDINGS, 37, 163-170 (1951) is in part incorrect. This theorem should read as follows: If I is an ideal of a semiring S, then S is homomorphic to the difference semiring S = S - I. SAMUEL BOURNE Downloaded by guest on September 30, 2021 Vol.. 37, 1951 31MA THEMA TICS: S. BOURNE 163 a (W1(%qw(2) ..W(n)) However, the coefficient of u? is 1. Hence all the coefficients are rational numbers. Letting u2 = 1, ua = U4 = ... = = Owe seev(2) for (i = 1, 2, ...,n) are all algebraic numbers. Similarly, we have vj/) for i, j = 1, 2, ..., n are all algebraic numbers. Let K = R(vP2), 3(l)M, ..., P.(l)), where R is the rational numbers (i.e., K is the least algebraic extension of R containing v2M'), . ..,vI (1)). As ul + P2(1)u2 + . + Pn(l)un $ Ounless u, = u2 = ... = un =O, we see that (K:R) = n' n. Hence, consider the n' different isomorphisms of K leaving R fixed. As they leave R fixed they leave the coefficients of the u's in the expansion of (9) fixed. By Hilbert's theorem on the uniqueness of the irreducible factors of a polynomial in n variables, we see that the n' iso- morphisms of K must merely permute the linear factors on the right side of (9). As all isomorphisms of K act differently on ul + u2 2(1) + .
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